{"id":7098,"date":"2023-10-01T18:26:36","date_gmt":"2023-10-01T10:26:36","guid":{"rendered":"https:\/\/i007.vip:15443\/wordpress\/?p=7098"},"modified":"2023-10-01T18:26:36","modified_gmt":"2023-10-01T10:26:36","slug":"%e4%b8%80%e4%b8%aa%e6%9c%89%e8%b6%a3%e5%92%8c%e6%a3%98%e6%89%8b%e7%9a%84-javascript-%e7%a4%ba%e4%be%8b%e5%88%97%e8%a1%a8%e3%80%82","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/7098","title":{"rendered":"\u4e00\u4e2a\u6709\u8da3\u548c\u68d8\u624b\u7684 JavaScript \u793a\u4f8b\u5217\u8868\u3002"},"content":{"rendered":"<p dir=\"auto\"><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md\">cc from<\/a><\/p>\n<p dir=\"auto\">\n<p dir=\"auto\">JavaScript \u662f\u4e00\u4e2a\u4e0d\u9519\u7684\u8bed\u8a00\u3002\u5b83\u7684\u8bed\u6cd5\u7b80\u5355\uff0c\u751f\u6001\u7cfb\u7edf\u4e5f\u5f88\u5e9e\u5927\uff0c\u6700\u91cd\u8981\u7684\u662f\uff0c\u5b83\u62e5\u6709\u6700\u4f1f\u5927\u7684\u793e\u533a\u529b\u91cf\u3002<\/p>\n<p dir=\"auto\">\u6211\u4eec\u77e5\u9053\uff0cJavaScript \u662f\u4e00\u4e2a\u975e\u5e38\u6709\u8da3\u7684\u8bed\u8a00\uff0c\u4f46\u540c\u65f6\u4e5f\u5145\u6ee1\u4e86\u5404\u79cd\u5947\u602a\u7684\u884c\u4e3a\u3002\u8fd9\u4e9b\u5947\u602a\u7684\u884c\u4e3a\u6709\u65f6\u4f1a\u641e\u7838\u6211\u4eec\u7684\u65e5\u5e38\u5de5\u4f5c\uff0c\u6709\u65f6\u5219\u4f1a\u8ba9\u6211\u4eec\u5fcd\u4fca\u4e0d\u7981\u3002<\/p>\n<p dir=\"auto\">WTFJS \u7684\u7075\u611f\u6e90\u4e8e\u00a0<a href=\"https:\/\/twitter.com\/brianleroux\" rel=\"nofollow\">Brian Leroux<\/a>\u3002\u8fd9\u4e2a\u5217\u8868\u53d7\u5230\u4ed6\u00a0<a href=\"https:\/\/www.youtube.com\/watch?v=et8xNAc2ic8\" rel=\"nofollow\">\u5728 2012 \u5e74\u7684 dotJS \u4e0a\u7684\u6f14\u8bb2\u00a0<strong>\u201cWTFJS\u201d<\/strong><\/a>\u00a0\u7684\u9ad8\u5ea6\u542f\u53d1\uff1a<\/p>\n<p dir=\"auto\"><a href=\"https:\/\/www.youtube.com\/watch?v=et8xNAc2ic8\" rel=\"nofollow\"><img decoding=\"async\" src=\"https:\/\/camo.githubusercontent.com\/d9b9b990b8668660583a06ec1b3d7758352a3a502700ff778667924c63f75126\/68747470733a2f2f696d672e796f75747562652e636f6d2f76692f657438784e4163326963382f302e6a7067\" alt=\"dotJS 2012 - Brian Leroux - WTFJS\" data-canonical-src=\"https:\/\/img.youtube.com\/vi\/et8xNAc2ic8\/0.jpg\" \/><\/a><\/p>\n<h1 id=\"user-content-\u9002\u7528\u4e8e-nodejs-\u7684\u6307\u5357\u624b\u518c\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E9%80%82%E7%94%A8%E4%BA%8E-nodejs-%E7%9A%84%E6%8C%87%E5%8D%97%E6%89%8B%E5%86%8C\">\u9002\u7528\u4e8e NodeJS \u7684\u6307\u5357\u624b\u518c<\/a><\/h1>\n<p dir=\"auto\">\u4f60\u53ef\u4ee5\u901a\u8fc7\u00a0<code>npm<\/code>\u00a0\u5b89\u88c5\u8be5\u9879\u76ee\u7684\u6307\u5357\u624b\u518c\u3002\u53ea\u9700\u8fd0\u884c\uff1a<\/p>\n<div class=\"snippet-clipboard-content notranslate position-relative overflow-auto\">\n<pre class=\"notranslate\"><code>$ npm install -g wtfjs\r\n<\/code><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u7136\u540e\u5728\u547d\u4ee4\u884c\u4e2d\u8fd0\u884c\u00a0<code>wtfjs<\/code>\uff0c\u5c06\u4f1a\u5728\u547d\u4ee4\u884c\u4e2d\u6253\u5f00\u624b\u518c\u5e76\u8df3\u8f6c\u81f3\u4f60\u9009\u62e9\u7684\u9875\u6570\u00a0<code>$PAGER<\/code>\u3002\u8fd9\u4e0d\u662f\u5fc5\u9700\u7684\u6b65\u9aa4\uff0c\u4f60\u4e5f\u53ef\u4ee5\u7ee7\u7eed\u5728\u8fd9\u91cc\u9605\u8bfb\u3002<\/p>\n<p dir=\"auto\">\u6e90\u7801\u5728\u6b64\u5904:\u00a0<a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\">https:\/\/github.com\/denysdovhan\/wtfjs<\/a><\/p>\n<h1 id=\"user-content-\u7ffb\u8bd1\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%BF%BB%E8%AF%91\">\u7ffb\u8bd1<\/a><\/h1>\n<p dir=\"auto\">\u5982\u4eca\uff0c<strong>wtfjs<\/strong>\u00a0\u5df2\u88ab\u7ffb\u8bd1\u6210\u591a\u79cd\u8bed\u8a00:<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md\">\u4e2d\u6587<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-hi.md\">\u0939\u093f\u0902\u0926\u0940<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-fr-fr.md\">Fran\u00e7ais<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-pt-br.md\">Portugu\u00eas do Brasil<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-pl-pl.md\">Polski<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-it-it.md\">Italiano<\/a><\/li>\n<li><a href=\"https:\/\/habr.com\/ru\/company\/mailru\/blog\/335292\/\" rel=\"nofollow\">Russian<\/a>\u00a0(on Habr.com)<\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-kr.md\">\ud55c\uad6d\uc5b4<\/a><\/li>\n<\/ul>\n<p dir=\"auto\"><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/CONTRIBUTING.md#translations\"><strong>\u70b9\u6b64\u6dfb\u52a0\u65b0\u8bed\u8a00\u7684\u7ffb\u8bd1<\/strong><\/a><\/p>\n<p dir=\"auto\"><strong>\u6ce8\u610f:<\/strong>\u00a0\u7ffb\u8bd1\u7531\u8be5\u8bed\u8a00\u7684\u8bd1\u8005\u7ef4\u62a4\uff0c\u56e0\u6b64\u53ef\u80fd\u7f3a\u5931\u90e8\u5206\u4f8b\u5b50\uff0c\u6216\u5b58\u5728\u8fc7\u65f6\u7684\u4f8b\u5b50\u7b49\u3002<\/p>\n<h1 id=\"user-content-table-of-contents\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#table-of-contents\">Table of Contents<\/a><\/h1>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E5%88%9D%E8%A1%B7\">?? \u521d\u8877<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E7%AC%A6%E5%8F%B7\">\u270d? \u7b26\u53f7<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E4%BE%8B%E5%AD%90\">? \u4f8b\u5b50<\/a>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E7%AD%89%E4%BA%8E-\"><code>[]<\/code>\u00a0\u7b49\u4e8e\u00a0<code>![]<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#true-%E4%B8%8D%E7%AD%89%E4%BA%8E-%E4%B9%9F%E4%B8%8D%E7%AD%89%E4%BA%8E-\"><code>true<\/code>\u00a0\u4e0d\u7b49\u4e8e\u00a0<code>![]<\/code>\uff0c\u4e5f\u4e0d\u7b49\u4e8e\u00a0<code>[]<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#true-%E6%98%AF-false\">true \u662f false<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#banana\">baNaNa<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#nan-%E4%B8%8D%E6%98%AF-nan\"><code>NaN<\/code>\u00a0\u4e0d\u662f\u00a0<code>NaN<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%A5%87%E6%80%AA%E7%9A%84-objectis-%E5%92%8C-\">\u5947\u602a\u7684\u00a0<code>Object.is()<\/code>\u00a0\u548c\u00a0<code>===<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%AE%83%E6%98%AF-fail\">\u5b83\u662f fail<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E6%98%AF%E7%9C%9F%E5%80%BC%E4%BD%86%E4%B8%8D%E7%AD%89%E4%BA%8E-true\"><code>[]<\/code>\u00a0\u662f\u771f\u503c\uff0c\u4f46\u4e0d\u7b49\u4e8e\u00a0<code>true<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#null-%E6%98%AF%E5%81%87%E5%80%BC%E4%BD%86%E5%8F%88%E4%B8%8D%E7%AD%89%E4%BA%8E-false\"><code>null<\/code>\u00a0\u662f\u5047\u503c\uff0c\u4f46\u53c8\u4e0d\u7b49\u4e8e\u00a0<code>false<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#documentall-%E6%98%AF%E4%B8%80%E4%B8%AA-object%E4%BD%86%E5%8F%88%E5%90%8C%E6%97%B6%E6%98%AF-undefined\"><code>document.all<\/code>\u00a0\u662f\u4e00\u4e2a object\uff0c\u4f46\u53c8\u540c\u65f6\u662f undefined<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%9C%80%E5%B0%8F%E5%80%BC%E5%A4%A7%E4%BA%8E%E9%9B%B6\">\u6700\u5c0f\u503c\u5927\u4e8e\u96f6<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%87%BD%E6%95%B0%E4%B8%8D%E6%98%AF%E5%87%BD%E6%95%B0\">\u51fd\u6570\u4e0d\u662f\u51fd\u6570<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%95%B0%E7%BB%84%E7%9B%B8%E5%8A%A0\">\u6570\u7ec4\u76f8\u52a0<\/a><\/li>\n<\/ul>\n<\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%95%B0%E7%BB%84%E4%B8%AD%E7%9A%84%E5%B0%BE%E9%80%97%E5%8F%B7\">\u6570\u7ec4\u4e2d\u7684\u5c3e\u9017\u53f7<\/a>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%95%B0%E7%BB%84%E7%9A%84%E7%9B%B8%E7%AD%89%E6%80%A7%E6%98%AF%E6%B7%B1%E6%B0%B4%E7%8C%9B%E5%85%BD\">\u6570\u7ec4\u7684\u76f8\u7b49\u6027\u662f\u6df1\u6c34\u731b\u517d<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#undefined-%E5%92%8C-number\"><code>undefined<\/code>\u00a0\u548c\u00a0<code>Number<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#parseint-%E6%98%AF%E4%B8%80%E4%B8%AA%E5%9D%8F%E8%9B%8B\"><code>parseInt<\/code>\u00a0\u662f\u4e00\u4e2a\u574f\u86cb<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#true-%E5%92%8C-false-%E7%9A%84%E6%95%B0%E5%AD%A6%E8%BF%90%E7%AE%97\"><code>true<\/code>\u00a0\u548c\u00a0<code>false<\/code>\u00a0\u7684\u6570\u5b66\u8fd0\u7b97<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#html-%E6%B3%A8%E9%87%8A%E5%9C%A8-javascript-%E4%B8%AD%E6%9C%89%E6%95%88\">HTML \u6ce8\u91ca\u5728 JavaScript \u4e2d\u6709\u6548<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#nan-%E4%B8%8D%E6%98%AF%E4%B8%80%E4%B8%AA%E6%95%B0%E5%80%BC\"><code>NaN<\/code>\u00a0<del>\u4e0d\u662f<\/del>\u4e00\u4e2a\u6570\u503c<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E5%92%8C-null-%E6%98%AF%E5%AF%B9%E8%B1%A1\"><code>[]<\/code>\u00a0\u548c\u00a0<code>null<\/code>\u00a0\u662f\u5bf9\u8c61<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%A5%9E%E5%A5%87%E7%9A%84%E6%95%B0%E5%AD%97%E5%A2%9E%E9%95%BF\">\u795e\u5947\u7684\u6570\u5b57\u589e\u957f<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#01--02-%E7%B2%BE%E5%BA%A6%E8%AE%A1%E7%AE%97\"><code>0.1 + 0.2<\/code>\u00a0\u7cbe\u5ea6\u8ba1\u7b97<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%89%A9%E5%B1%95%E6%95%B0%E5%AD%97%E7%9A%84%E6%96%B9%E6%B3%95\">\u6269\u5c55\u6570\u5b57\u7684\u65b9\u6cd5<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E4%B8%89%E4%B8%AA%E6%95%B0%E5%AD%97%E7%9A%84%E6%AF%94%E8%BE%83\">\u4e09\u4e2a\u6570\u5b57\u7684\u6bd4\u8f83<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%9C%89%E8%B6%A3%E7%9A%84%E6%95%B0%E5%AD%A6\">\u6709\u8da3\u7684\u6570\u5b66<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E7%9A%84%E5%8A%A0%E6%B3%95\">\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u52a0\u6cd5<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%AD%97%E7%AC%A6%E4%B8%B2%E4%B8%8D%E6%98%AF-string-%E7%9A%84%E5%AE%9E%E4%BE%8B\">\u5b57\u7b26\u4e32\u4e0d\u662f\u00a0<code>String<\/code>\u00a0\u7684\u5b9e\u4f8b<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%94%A8%E5%8F%8D%E5%BC%95%E5%8F%B7%E8%B0%83%E7%94%A8%E5%87%BD%E6%95%B0\">\u7528\u53cd\u5f15\u53f7\u8c03\u7528\u51fd\u6570<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%88%B0%E5%BA%95-call-%E4%BA%86%E8%B0%81\">\u5230\u5e95 call \u4e86\u8c01<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#constructor-%E5%B1%9E%E6%80%A7\"><code>constructor<\/code>\u00a0\u5c5e\u6027<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%B0%86%E5%AF%B9%E8%B1%A1%E5%81%9A%E4%B8%BA%E5%8F%A6%E4%B8%80%E4%B8%AA%E5%AF%B9%E8%B1%A1%E7%9A%84-key\">\u5c06\u5bf9\u8c61\u505a\u4e3a\u53e6\u4e00\u4e2a\u5bf9\u8c61\u7684 key<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E8%AE%BF%E9%97%AE%E5%8E%9F%E5%9E%8B-__proto__\">\u8bbf\u95ee\u539f\u578b\u00a0<code>__proto__<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-object-\"><code>`${{Object}}`<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E4%BD%BF%E7%94%A8%E9%BB%98%E8%AE%A4%E5%80%BC%E8%A7%A3%E6%9E%84\">\u4f7f\u7528\u9ed8\u8ba4\u503c\u89e3\u6784<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%82%B9%E5%92%8C%E6%89%A9%E5%B1%95%E8%BF%90%E7%AE%97%E7%AC%A6\">\u70b9\u548c\u6269\u5c55\u8fd0\u7b97\u7b26<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%A0%87%E7%AD%BE\">\u6807\u7b7e<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%B5%8C%E5%A5%97%E6%A0%87%E7%AD%BE\">\u5d4c\u5957\u6807\u7b7e<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E9%98%B4%E9%99%A9%E7%9A%84-trycatch\">\u9634\u9669\u7684\u00a0<code>try..catch<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E8%BF%99%E6%98%AF%E5%A4%9A%E9%87%8D%E7%BB%A7%E6%89%BF%E5%90%97\">\u8fd9\u662f\u591a\u91cd\u7ee7\u627f\u5417\uff1f<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#yield-%E8%BF%94%E5%9B%9E%E8%87%AA%E8%BA%AB%E7%9A%84%E7%94%9F%E6%88%90%E5%99%A8\">yield \u8fd4\u56de\u81ea\u8eab\u7684\u751f\u6210\u5668<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%B1%BB%E7%9A%84%E7%B1%BB\">\u7c7b\u7684\u7c7b<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E4%B8%8D%E5%8F%AF%E8%BD%AC%E6%8D%A2%E7%B1%BB%E5%9E%8B%E7%9A%84%E5%AF%B9%E8%B1%A1\">\u4e0d\u53ef\u8f6c\u6362\u7c7b\u578b\u7684\u5bf9\u8c61<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%A3%98%E6%89%8B%E7%9A%84%E7%AE%AD%E5%A4%B4%E5%87%BD%E6%95%B0\">\u68d8\u624b\u7684\u7bad\u5934\u51fd\u6570<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%AE%AD%E5%A4%B4%E5%87%BD%E6%95%B0%E4%B8%8D%E8%83%BD%E4%BD%9C%E4%B8%BA%E6%9E%84%E9%80%A0%E5%87%BD%E6%95%B0\">\u7bad\u5934\u51fd\u6570\u4e0d\u80fd\u4f5c\u4e3a\u6784\u9020\u51fd\u6570<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#arguments-%E5%92%8C%E7%AE%AD%E5%A4%B4%E5%87%BD%E6%95%B0\"><code>arguments<\/code>\u00a0\u548c\u7bad\u5934\u51fd\u6570<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%A3%98%E6%89%8B%E7%9A%84%E8%BF%94%E5%9B%9E\">\u68d8\u624b\u7684\u8fd4\u56de<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%AF%B9%E8%B1%A1%E7%9A%84%E9%93%BE%E5%BC%8F%E8%B5%8B%E5%80%BC\">\u5bf9\u8c61\u7684\u94fe\u5f0f\u8d4b\u503c<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E4%BD%BF%E7%94%A8%E6%95%B0%E7%BB%84%E8%AE%BF%E9%97%AE%E5%AF%B9%E8%B1%A1%E5%B1%9E%E6%80%A7\">\u4f7f\u7528\u6570\u7ec4\u8bbf\u95ee\u5bf9\u8c61\u5c5e\u6027<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#numbertofixed-%E6%98%BE%E7%A4%BA%E4%B8%8D%E5%90%8C%E7%9A%84%E6%95%B0%E5%AD%97\"><code>Number.toFixed()<\/code>\u00a0\u663e\u793a\u4e0d\u540c\u7684\u6570\u5b57<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#min-%E5%A4%A7%E4%BA%8E-max\"><code>min<\/code>\u00a0\u5927\u4e8e\u00a0<code>max<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%AF%94%E8%BE%83-null-%E5%92%8C-0\">\u6bd4\u8f83\u00a0<code>null<\/code>\u00a0\u548c\u00a0<code>0<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%9B%B8%E5%90%8C%E5%8F%98%E9%87%8F%E9%87%8D%E5%A4%8D%E5%A3%B0%E6%98%8E\">\u76f8\u540c\u53d8\u91cf\u91cd\u590d\u58f0\u660e<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#arrayprototypesort-%E7%9A%84%E9%BB%98%E8%AE%A4%E8%A1%8C%E4%B8%BA\">Array.prototype.sort() \u7684\u9ed8\u8ba4\u884c\u4e3a<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#resolve-%E4%B8%8D%E4%BC%9A%E8%BF%94%E5%9B%9E-promise-%E5%AE%9E%E4%BE%8B\">resolve() \u4e0d\u4f1a\u8fd4\u56de Promise \u5b9e\u4f8b<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E6%98%AF-undefined\"><code>{}{}<\/code>\u00a0\u662f undefined<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#arguments-%E7%BB%91%E5%AE%9A\"><code>arguments<\/code>\u00a0\u7ed1\u5b9a<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%9D%A5%E8%87%AA%E5%9C%B0%E7%8B%B1%E7%9A%84-alert\">\u6765\u81ea\u5730\u72f1\u7684\u00a0<code>alert<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%B2%A1%E6%9C%89%E5%B0%BD%E5%A4%B4%E7%9A%84%E8%AE%A1%E6%97%B6\">\u6ca1\u6709\u5c3d\u5934\u7684\u8ba1\u65f6<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#settimeout-%E5%AF%B9%E8%B1%A1\"><code>setTimeout<\/code>\u00a0\u5bf9\u8c61<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%82%B9%E7%82%B9%E8%BF%90%E7%AE%97%E7%AC%A6\">\u70b9\u70b9\u8fd0\u7b97\u7b26<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%86%8D-new-%E4%B8%80%E6%AC%A1\">\u518d new \u4e00\u6b21<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E4%BD%A0%E5%BA%94%E8%AF%A5%E7%94%A8%E4%B8%8A%E5%88%86%E5%8F%B7\">\u4f60\u5e94\u8be5\u7528\u4e0a\u5206\u53f7<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%94%A8%E7%A9%BA%E6%A0%BC%E5%88%86%E5%89%B2split%E5%AD%97%E7%AC%A6%E4%B8%B2\">\u7528\u7a7a\u683c\u5206\u5272\uff08split\uff09\u5b57\u7b26\u4e32<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%AF%B9%E5%AD%97%E7%AC%A6%E4%B8%B2-stringify\">\u5bf9\u5b57\u7b26\u4e32 stringify<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%AF%B9%E6%95%B0%E5%AD%97%E5%92%8C-true-%E7%9A%84%E9%9D%9E%E4%B8%A5%E6%A0%BC%E7%9B%B8%E7%AD%89%E6%AF%94%E8%BE%83\">\u5bf9\u6570\u5b57\u548c\u00a0<code>true<\/code>\u00a0\u7684\u975e\u4e25\u683c\u76f8\u7b49\u6bd4\u8f83<\/a><\/li>\n<\/ul>\n<\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%85%B6%E4%BB%96%E8%B5%84%E6%BA%90\">\u5176\u4ed6\u8d44\u6e90<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E6%8D%90%E8%B5%A0%E6%94%AF%E6%8C%81\">? \u6350\u8d60\u652f\u6301<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AE%B8%E5%8F%AF%E8%AF%81\">? \u8bb8\u53ef\u8bc1<\/a><\/li>\n<\/ul>\n<h1 id=\"user-content--\u521d\u8877\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E5%88%9D%E8%A1%B7\">?? \u521d\u8877<\/a><\/h1>\n<blockquote>\n<p dir=\"auto\">\u53ea\u662f\u56e0\u4e3a\u597d\u73a9<\/p>\n<p dir=\"auto\">\u2014\u00a0<em><a href=\"https:\/\/en.m.wikipedia.org\/wiki\/Just_for_Fun\" rel=\"nofollow\"><strong>\u201c\u53ea\u662f\u4e3a\u4e86\u597d\u73a9\uff1a\u4e00\u4e2a\u610f\u5916\u9769\u547d\u7684\u6545\u4e8b\u201d<\/strong><\/a>, Linus Torvalds<\/em><\/p>\n<\/blockquote>\n<p dir=\"auto\">\u8fd9\u4e2a\u5217\u8868\u7684\u4e3b\u8981\u76ee\u7684\u662f\u6536\u96c6\u4e00\u4e9b\u75af\u72c2\u7684\u4f8b\u5b50\uff0c\u5e76\u5c3d\u53ef\u80fd\u89e3\u91ca\u5b83\u4eec\u7684\u539f\u7406\u3002\u6211\u5f88\u559c\u6b22\u5b66\u4e60\u4ee5\u524d\u4e0d\u4e86\u89e3\u7684\u4e1c\u897f\u3002<\/p>\n<p dir=\"auto\">\u5982\u679c\u60a8\u662f\u521d\u5b66\u8005\uff0c\u60a8\u53ef\u4ee5\u6839\u636e\u6b64\u7b14\u8bb0\u6df1\u5165\u4e86\u89e3 JavaScript\u3002\u6211\u5e0c\u671b\u5b83\u4f1a\u6fc0\u52b1\u4f60\u5728\u9605\u8bfb\u89c4\u8303\u4e0a\u6295\u5165\u66f4\u591a\u65f6\u95f4\u548c\u7cbe\u529b\u3002<\/p>\n<p dir=\"auto\">\u5982\u679c\u60a8\u662f\u4e13\u4e1a\u5f00\u53d1\u4eba\u5458\uff0c\u60a8\u5c06\u4ece\u8fd9\u4e9b\u4f8b\u5b50\u4e2d\u770b\u5230\u4eba\u89c1\u4eba\u7231\u7684 JavaScript \u4e5f\u5145\u6ee1\u4e86\u975e\u9884\u671f\u7684\u8fb9\u754c\u884c\u4e3a\u3002<\/p>\n<p dir=\"auto\">\u603b\u4e4b\uff0c\u53e4\u4eba\u4e91\uff1a\u4e09\u4eba\u884c\uff0c\u5fc5\u6709\u6211\u5e08\u7109\u3002\u6211\u76f8\u4fe1\u8fd9\u4e9b\u4f8b\u5b50\u603b\u80fd\u8ba9\u4f60\u5b66\u4e60\u5230\u65b0\u7684\u77e5\u8bc6\u3002<\/p>\n<blockquote>\n<p dir=\"auto\"><strong>\u26a0\ufe0f\u00a0Note:<\/strong>\u00a0\u5982\u679c\u8fd9\u4e9b\u4f8b\u5b50\u5e2e\u52a9\u5230\u4f60\uff0c\u8bf7<a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-supporting\">\u52a1\u5fc5\u8d5e\u52a9\u6536\u96c6\u4e86\u8fd9\u4e9b\u4f8b\u5b50\u7684\u4f5c\u8005<\/a>.<\/p>\n<\/blockquote>\n<h1 id=\"user-content--\u7b26\u53f7\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E7%AC%A6%E5%8F%B7\">\u270d? \u7b26\u53f7<\/a><\/h1>\n<p dir=\"auto\"><strong><code>\/\/ -&gt;<\/code><\/strong>\u00a0\u8868\u793a\u8868\u8fbe\u5f0f\u7684\u7ed3\u679c\u3002\u4f8b\u5982\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">1<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 2<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\"><strong><code>\/\/ &gt;<\/code><\/strong>\u00a0\u8868\u793a\u00a0<code>console.log<\/code>\u00a0\u7b49\u8f93\u51fa\u7684\u7ed3\u679c\u3002\u4f8b\u5982\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"hello, world!\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ &gt; hello, world!<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\"><strong><code>\/\/<\/code><\/strong>\u00a0\u5219\u662f\u7528\u4e8e\u89e3\u91ca\u7684\u6ce8\u91ca\u3002\u4f8b\u5982\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/ \u5c06\u4e00\u4e2a\u51fd\u6570\u8d4b\u503c\u7ed9 foo \u5e38\u91cf<\/span>\r\n<span class=\"pl-k\">const<\/span> <span class=\"pl-en\">foo<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h1 id=\"user-content--\u4f8b\u5b50\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E4%BE%8B%E5%AD%90\">? \u4f8b\u5b50<\/a><\/h1>\n<h2 id=\"user-content--\u7b49\u4e8e-\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E7%AD%89%E4%BA%8E-\"><code>[]<\/code>\u00a0\u7b49\u4e8e\u00a0<code>![]<\/code><\/a><\/h2>\n<p dir=\"auto\">\u6570\u7ec4\u7b49\u4e8e\u4e00\u4e2a\u6570\u7ec4\u53d6\u53cd\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u62bd\u8c61\u76f8\u7b49\u8fd0\u7b97\u7b26\u4f1a\u5c06\u5176\u4e24\u7aef\u7684\u8868\u8fbe\u5f0f\u8f6c\u6362\u4e3a\u6570\u5b57\u503c\u8fdb\u884c\u6bd4\u8f83\uff0c\u5c3d\u7ba1\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u5de6\u53f3\u4e24\u7aef\u5747\u88ab\u8f6c\u6362\u4e3a\u00a0<code>0<\/code>\uff0c\u4f46\u539f\u56e0\u5404\u4e0d\u76f8\u540c\u3002\u6570\u7ec4\u603b\u662f\u771f\u503c\uff08truthy\uff09,\u56e0\u6b64\u53f3\u503c\u7684\u6570\u7ec4\u53d6\u53cd\u540e\u603b\u662f\u4e3a\u00a0<code>false<\/code>\uff0c\u7136\u540e\u5728\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83\u4e2d\u88ab\u88ab\u7c7b\u578b\u8f6c\u6362\u4e3a\u00a0<code>0<\/code>\u3002\u800c\u5de6\u503c\u5219\u662f\u53e6\u4e00\u79cd\u60c5\u5f62\uff0c\u7a7a\u6570\u7ec4\u6ca1\u6709\u88ab\u8f6c\u6362\u4e3a\u5e03\u5c14\u503c\u7684\u8bdd\uff0c\u5c3d\u7ba1\u5728\u903b\u8f91\u4e0a\u662f\u771f\u503c\uff08truthy\uff09\uff0c\u4f46\u5728\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83\u4e2d\uff0c\u4f1a\u88ab\u7c7b\u578b\u8f6c\u6362\u4e3a\u6570\u5b57\u00a0<code>0<\/code>\u3002<\/p>\n<p dir=\"auto\">\u8be5\u8868\u8fbe\u5f0f\u7684\u8fd0\u7b97\u6b65\u9aa4\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">+<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">0<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">false<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">0<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4e86\u89e3\u66f4\u591a\uff1a<a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-is-truthy-but-not-true\"><code>[]<\/code>\u00a0\u662f\u771f\u503c\uff0c\u4f46\u5e76\u975e\u00a0<code>true<\/code><\/a>.<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-logical-not-operator\" rel=\"nofollow\"><strong>12.5.9<\/strong>\u00a0\u903b\u8f91\u975e\u8fd0\u7b97\u7b26 (<code>!<\/code>)<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-abstract-equality-comparison\" rel=\"nofollow\"><strong>7.2.13<\/strong>\u00a0\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-true-\u4e0d\u7b49\u4e8e-\u4e5f\u4e0d\u7b49\u4e8e-\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#true-%E4%B8%8D%E7%AD%89%E4%BA%8E-%E4%B9%9F%E4%B8%8D%E7%AD%89%E4%BA%8E-\"><code>true<\/code>\u00a0\u4e0d\u7b49\u4e8e\u00a0<code>![]<\/code>\uff0c\u4e5f\u4e0d\u7b49\u4e8e\u00a0<code>[]<\/code><\/a><\/h2>\n<p dir=\"auto\">\u6570\u7ec4\u4e0d\u7b49\u4e8e\u00a0<code>true<\/code>\uff0c\u4f46\u6570\u7ec4\u53d6\u53cd\u4e5f\u4e0d\u7b49\u4e8e\u00a0<code>true<\/code>\uff1b \u6570\u7ec4\u7b49\u4e8e\u00a0<code>false<\/code>\u6570\u7ec4\u53d6\u53cd\u4e5f\u7b49\u4e8e\u00a0<code>false<\/code>\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n\r\n<span class=\"pl-c1\">false<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-c1\">false<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-1\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-1\">? \u8bf4\u660e:<\/a><\/h3>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ \u6839\u636e\u89c4\u8303<\/span>\r\n\r\n<span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n\r\n<span class=\"pl-en\">toNumber<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 1<\/span>\r\n<span class=\"pl-en\">toNumber<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 0<\/span>\r\n\r\n<span class=\"pl-c1\">1<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n\r\n<span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n\r\n<span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">false<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">false<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-c1\">false<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ \u6839\u636e\u89c4\u8303<\/span>\r\n\r\n<span class=\"pl-c1\">false<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n\r\n<span class=\"pl-en\">toNumber<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">false<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 0<\/span>\r\n<span class=\"pl-en\">toNumber<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 0<\/span>\r\n\r\n<span class=\"pl-c1\">0<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n\r\n<span class=\"pl-c1\">false<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n\r\n<span class=\"pl-c1\">false<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">false<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/262.ecma-international.org\/11.0\/index.html#sec-abstract-equality-comparison\" rel=\"nofollow\"><strong>7.2.15<\/strong>\u00a0\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-true-\u662f-false\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#true-%E6%98%AF-false\">true \u662f false<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-s\">\"false\"<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-s\">\"true\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-s\">\"false\"<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-s\">\"true\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-2\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-2\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8003\u8651\u4ee5\u4e0b\u6b65\u9aa4\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/ true \u662f\u771f\u503c\uff08truthy\uff09\uff0c\u5e76\u4e14\u9690\u5f0f\u8f6c\u6362\u4e3a\u6570\u5b571\uff0c\u800c\u5b57\u7b26\u4e32 'true' \u4f1a\u88ab\u8f6c\u6362\u4e3a NaN\u3002<\/span>\r\n<span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">\"true\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-c1\">false<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">\"false\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ 'false' \u4e0d\u662f\u7a7a\u5b57\u7b26\u4e32\uff0c\u6240\u4ee5\u5b83\u7684\u503c\u662f true<\/span>\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-s\">\"false\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-s\">\"true\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-abstract-equality-comparison\" rel=\"nofollow\"><strong>7.2.13<\/strong>\u00a0\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-banana\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#banana\">baNaNa<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-s\">\"b\"<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-s\">\"a\"<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">+<\/span><span class=\"pl-s\">\"a\"<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-s\">\"a\"<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u8fd9\u662f\u7528 JavaScript \u5199\u7684\u8001\u6d3e\u7b11\u8bdd\uff0c\u539f\u7248\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-s\">\"foo\"<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">+<\/span><span class=\"pl-s\">\"bar\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'fooNaN'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-3\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-3\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8fd9\u4e2a\u8868\u8fbe\u5f0f\u53ef\u4ee5\u8f6c\u5316\u6210\u00a0<code>'foo' + (+'bar')<\/code>\uff0c\u4f46\u65e0\u6cd5\u5c06<code>'bar'<\/code>\u5f3a\u5236\u8f6c\u5316\u6210\u6570\u503c\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-addition-operator-plus\" rel=\"nofollow\"><strong>12.8.3<\/strong>\u00a0\u52a0\u6cd5\u8fd0\u7b97\u7b26 (<code>+<\/code>)<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-unary-plus-operator\" rel=\"nofollow\">12.5.6 \u4e00\u5143 + \u8fd0\u7b97\u7b26<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-nan-\u4e0d\u662f-nan\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#nan-%E4%B8%8D%E6%98%AF-nan\"><code>NaN<\/code>\u00a0\u4e0d\u662f\u00a0<code>NaN<\/code><\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-v\">NaN<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-4\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-4\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u89c4\u8303\u4e25\u683c\u5b9a\u4e49\u4e86\u8fd9\u79cd\u884c\u4e3a\u80cc\u540e\u7684\u903b\u8f91\uff1a<\/p>\n<blockquote>\n<ol dir=\"auto\">\n<li>\u5982\u679c\u00a0<code>Type(x)<\/code>\u00a0\u4e0d\u540c\u4e8e\u00a0<code>Type(y)<\/code>\uff0c\u8fd4\u56de\u00a0<strong>false<\/strong>\u3002<\/li>\n<li>\u5982\u679c\u00a0<code>Type(x)<\/code>\u00a0\u6570\u503c, \u7136\u540e\n<ol dir=\"auto\">\n<li>\u5982\u679c\u00a0<code>x<\/code>\u00a0\u662f\u00a0<strong>NaN<\/strong>\uff0c\u8fd4\u56de\u00a0<strong>false<\/strong>\u3002<\/li>\n<li>\u5982\u679c\u00a0<code>y<\/code>\u00a0\u662f\u00a0<strong>NaN<\/strong>\uff0c\u8fd4\u56de\u00a0<strong>false<\/strong>\u3002<\/li>\n<li>\u2026\u2026<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<p dir=\"auto\">\u2014\u00a0<a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-strict-equality-comparison\" rel=\"nofollow\"><strong>7.2.14<\/strong>\u00a0\u4e25\u683c\u6a21\u5f0f\u76f8\u7b49\u6bd4\u8f83<\/a><\/p>\n<\/blockquote>\n<p dir=\"auto\">\u6839\u636e IEEE \u5bf9 NaN \u7684\u5b9a\u4e49\uff1a<\/p>\n<blockquote>\n<p dir=\"auto\">\u6709\u56db\u79cd\u53ef\u80fd\u7684\u76f8\u4e92\u6392\u65a5\u7684\u5173\u7cfb\uff1a\u5c0f\u4e8e\u3001\u7b49\u4e8e\u3001\u5927\u4e8e\u548c\u65e0\u5e8f\u3002\u5f53\u6bd4\u8f83\u64cd\u4f5c\u4e2d\u81f3\u5c11\u4e00\u4e2a\u64cd\u4f5c\u6570\u662f NaN \u65f6\uff0c\u4fbf\u662f\u65e0\u5e8f\u7684\u5173\u7cfb\u3002\u6362\u53e5\u8bdd\u8bf4\uff0cNaN \u5bf9\u4efb\u4f55\u4e8b\u7269\u5305\u62ec\u5176\u672c\u8eab\u6bd4\u8f83\u90fd\u5e94\u5f53\u662f\u65e0\u5e8f\u5173\u7cfb\u3002<\/p>\n<p dir=\"auto\">\u2014 StackOverflow \u4e0a\u7684\u00a0<a href=\"https:\/\/stackoverflow.com\/questions\/1565164\/1573715#1573715\" rel=\"nofollow\">\u201c\u4e3a\u4ec0\u4e48\u5bf9\u4e8e IEEE754 NaN \u503c\u7684\u6240\u6709\u6bd4\u8f83\u8fd4\u56de false\uff1f\u201d<\/a><\/p>\n<\/blockquote>\n<h2 id=\"user-content-\u5947\u602a\u7684-objectis-\u548c-\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%A5%87%E6%80%AA%E7%9A%84-objectis-%E5%92%8C-\">\u5947\u602a\u7684\u00a0<code>Object.is()<\/code>\u00a0\u548c\u00a0<code>===<\/code><\/a><\/h2>\n<p dir=\"auto\"><code>Object.is()<\/code>\u00a0\u7528\u4e8e\u5224\u65ad\u4e24\u4e2a\u503c\u662f\u5426\u76f8\u540c\u3002\u548c\u00a0<code>===<\/code>\u00a0\u64cd\u4f5c\u7b26\u50cf\u4f5c\u7528\u7c7b\u4f3c\uff0c\u4f46\u5b83\u4e5f\u6709\u4e00\u4e9b\u5947\u602a\u7684\u884c\u4e3a\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-v\">Object<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">is<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-v\">NaN<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n\r\n<span class=\"pl-v\">Object<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">is<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">-<\/span><span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-c1\">-<\/span><span class=\"pl-c1\">0<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n\r\n<span class=\"pl-v\">Object<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">is<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">0<\/span> <span class=\"pl-c1\">\/<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-v\">NaN<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">0<\/span> <span class=\"pl-c1\">\/<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-5\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-5\">? \u8bf4\u660e:<\/a><\/h3>\n<p dir=\"auto\">\u5728 JavaScript \u201c\u8bed\u8a00\u201d\u4e2d\uff0c<code>NaN<\/code>\u00a0\u548c\u00a0<code>NaN<\/code>\u00a0\u7684\u503c\u662f\u76f8\u540c\u7684\uff0c\u4f46\u5374\u4e0d\u662f\u4e25\u683c\u76f8\u7b49\u3002<code>NaN === NaN<\/code>\u00a0\u8fd4\u56de false \u662f\u56e0\u4e3a\u5386\u53f2\u5305\u88b1\uff0c\u8bb0\u4f4f\u8fd9\u4e2a\u7279\u4f8b\u5c31\u884c\u4e86\u3002<\/p>\n<p dir=\"auto\">\u57fa\u4e8e\u540c\u6837\u7684\u539f\u56e0\uff0c<code>-0<\/code>\u00a0\u548c\u00a0<code>0<\/code>\u00a0\u662f\u4e25\u683c\u76f8\u7b49\u7684\uff0c\u4f46\u5b83\u4eec\u7684\u503c\u5374\u4e0d\u540c\u3002<\/p>\n<p dir=\"auto\">\u5173\u4e8e\u00a0<code>NaN === NaN<\/code>\u00a0\u7684\u66f4\u591a\u7ec6\u8282\uff0c\u8bf7\u53c2\u9605\u4e0a\u4e00\u4e2a\u4f8b\u5b50\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/tc39.es\/ecma262\/#sec-object.is\" rel=\"nofollow\">\u8fd9\u662f TC39 \u4e2d\u5173\u4e8e Object.is \u7684\u89c4\u8303<\/a><\/li>\n<li>MDN \u4e0a\u7684<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Equality_comparisons_and_sameness\" rel=\"nofollow\">\u76f8\u7b49\u6bd4\u8f83\u4e0e\u76f8\u540c\u503c\u6bd4\u8f83<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u5b83\u662f-fail\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%AE%83%E6%98%AF-fail\">\u5b83\u662f fail<\/a><\/h2>\n<p dir=\"auto\">\u4f60\u53ef\u80fd\u4e0d\u4f1a\u76f8\u4fe1\uff0c\u4f46\u2026\u2026<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">+<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span>\r\n  <span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">+<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span>\r\n  <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">+<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">+<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span>\r\n  <span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">+<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">+<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt; 'fail'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-6\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-6\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u5c06\u5927\u91cf\u7684\u7b26\u53f7\u5206\u89e3\u6210\u7247\u6bb5\uff0c\u6211\u4eec\u6ce8\u610f\u5230\uff0c\u4ee5\u4e0b\u8868\u8fbe\u5f0f\u7ecf\u5e38\u51fa\u73b0\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'false'<\/span>\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u6240\u4ee5\u6211\u4eec\u5c1d\u8bd5\u5c06\u00a0<code>[]<\/code>\u00a0\u548c\u00a0<code>false<\/code>\u00a0\u52a0\u8d77\u6765\u3002\u4f46\u662f\u56e0\u4e3a\u4e00\u4e9b\u5185\u90e8\u51fd\u6570\u8c03\u7528\uff08<code>binary + Operator<\/code>\u00a0&#8211; &gt;<code>ToPrimitive<\/code>\u00a0&#8211; &gt;<code>[[DefaultValue]<\/code>\u00a0]\uff09\uff0c\u6211\u4eec\u6700\u7ec8\u5c06\u53f3\u8fb9\u7684\u64cd\u4f5c\u6570\u8f6c\u6362\u4e3a\u4e00\u4e2a\u5b57\u7b26\u4e32\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toString<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ 'false'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u5c06\u5b57\u7b26\u4e32\u4f5c\u4e3a\u6570\u7ec4\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7<code>[0]<\/code>\u6765\u8bbf\u95ee\u5b83\u7684\u7b2c\u4e00\u4e2a\u5b57\u7b26\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-s\">\"false\"<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'f'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u5269\u4e0b\u7684\u90e8\u5206\u4ee5\u6b64\u7c7b\u63a8\uff0c\u4e0d\u8fc7\u6b64\u5904\u7684\u00a0<code>i<\/code>\u00a0\u5b57\u7b26\u662f\u6bd4\u8f83\u8ba8\u5de7\u7684\u3002<code>fail<\/code>\u00a0\u4e2d\u7684\u00a0<code>i<\/code>\u00a0\u6765\u81ea\u4e8e\u751f\u6210\u7684\u5b57\u7b26\u4e32\u00a0<code>falseundefined<\/code>\uff0c\u901a\u8fc7\u6307\u5b9a\u5e8f\u53f7\u00a0<code>['10']<\/code>\u00a0\u53d6\u5f97\u7684\u3002<\/p>\n<p dir=\"auto\">\u66f4\u591a\u7684\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span>          <span class=\"pl-c\">\/\/ -&gt; 0<\/span>\r\n<span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span>         <span class=\"pl-c\">\/\/ -&gt; 1<\/span>\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span>          <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span>           <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span>        <span class=\"pl-c\">\/\/ -&gt; undefined<\/span>\r\n<span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">\/<\/span> <span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span>  <span class=\"pl-c\">\/\/ -&gt; Infinity<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span>       <span class=\"pl-c\">\/\/ -&gt; \"[object Object]\"<\/span>\r\n<span class=\"pl-c1\">+<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span>           <span class=\"pl-c\">\/\/ -&gt; NaN<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<ul dir=\"auto\">\n<li><a href=\"http:\/\/patriciopalladino.com\/blog\/2012\/08\/09\/non-alphanumeric-javascript.html\" rel=\"nofollow\">\u70e7\u8111\u9884\u8b66\uff1a\u75af\u72c2\u7684 JavaScript<\/a><\/li>\n<li><a href=\"https:\/\/bluewings.github.io\/en\/writing-a-sentence-without-using-the-alphabet\/#weird-javascript-generator\" rel=\"nofollow\">\u5199\u4e2a\u53e5\u5b50\u5e72\u561b\u8981\u7528\u5b57\u6bcd<\/a>\u00a0\u2014 \u7528 JavaScript \u751f\u6210\u4efb\u610f\u77ed\u8bed<\/li>\n<\/ul>\n<h2 id=\"user-content--\u662f\u771f\u503c\u4f46\u4e0d\u7b49\u4e8e-true\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E6%98%AF%E7%9C%9F%E5%80%BC%E4%BD%86%E4%B8%8D%E7%AD%89%E4%BA%8E-true\"><code>[]<\/code>\u00a0\u662f\u771f\u503c\uff0c\u4f46\u4e0d\u7b49\u4e8e\u00a0<code>true<\/code><\/a><\/h2>\n<p dir=\"auto\">\u6570\u7ec4\u662f\u4e00\u4e2a\u771f\u503c\uff0c\u4f46\u5374\u4e0d\u7b49\u4e8e\u00a0<code>true<\/code>\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span>       <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">true<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-7\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-7\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u4ee5\u4e0b\u662f ECMA-262 \u89c4\u8303\u4e2d\u76f8\u5e94\u90e8\u5206\u7684\u94fe\u63a5\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-logical-not-operator\" rel=\"nofollow\"><strong>12.5.9<\/strong>\u00a0\u903b\u8f91\u975e\u8fd0\u7b97\u7b26 (<code>!<\/code>)<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-abstract-equality-comparison\" rel=\"nofollow\"><strong>7.2.13<\/strong>\u00a0\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-null-\u662f\u5047\u503c\u4f46\u53c8\u4e0d\u7b49\u4e8e-false\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#null-%E6%98%AF%E5%81%87%E5%80%BC%E4%BD%86%E5%8F%88%E4%B8%8D%E7%AD%89%E4%BA%8E-false\"><code>null<\/code>\u00a0\u662f\u5047\u503c\uff0c\u4f46\u53c8\u4e0d\u7b49\u4e8e\u00a0<code>false<\/code><\/a><\/h2>\n<p dir=\"auto\">\u5c3d\u7ba1\u00a0<code>null<\/code>\u00a0\u662f\u5047\u503c\uff0c\u4f46\u5b83\u4e0d\u7b49\u4e8e\u00a0<code>false<\/code>\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">false<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4f46\u662f\uff0c\u522b\u7684\u88ab\u5f53\u4f5c\u5047\u503c\u7684\u5374\u7b49\u4e8e\u00a0<code>false<\/code>\uff0c\u5982\u00a0<code>0<\/code>\u00a0\u6216\u00a0<code>''<\/code>\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">0<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">false<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-s\">\"\"<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">false<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-8\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-8\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8ddf\u524d\u9762\u7684\u4f8b\u5b50\u76f8\u540c\u3002\u8fd9\u662f\u4e00\u4e2a\u76f8\u5e94\u7684\u94fe\u63a5\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-abstract-equality-comparison\" rel=\"nofollow\"><strong>7.2.13<\/strong>\u00a0\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-documentall-\u662f\u4e00\u4e2a-object\u4f46\u53c8\u540c\u65f6\u662f-undefined\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#documentall-%E6%98%AF%E4%B8%80%E4%B8%AA-object%E4%BD%86%E5%8F%88%E5%90%8C%E6%97%B6%E6%98%AF-undefined\"><code>document.all<\/code>\u00a0\u662f\u4e00\u4e2a object\uff0c\u4f46\u53c8\u540c\u65f6\u662f undefined<\/a><\/h2>\n<blockquote>\n<p dir=\"auto\">\u26a0\ufe0f\u00a0\u8fd9\u662f\u6d4f\u89c8\u5668 API \u7684\u4e00\u90e8\u5206\uff0c\u5bf9\u4e8e Node.js \u73af\u5883\u65e0\u6548\u00a0\u26a0\ufe0f<\/p>\n<\/blockquote>\n<p dir=\"auto\">\u5c3d\u7ba1 document.all \u662f\u4e00\u4e2a\u7c7b\u6570\u7ec4\u5bf9\u8c61\uff08array-like object\uff09\uff0c\u5e76\u4e14\u901a\u8fc7\u5b83\u53ef\u4ee5\u8bbf\u95ee\u9875\u9762\u4e2d\u7684 DOM \u8282\u70b9\uff0c\u4f46\u5728\u901a\u8fc7\u00a0<code>typeof<\/code>\u00a0\u7684\u68c0\u6d4b\u7ed3\u679c\u662f\u00a0<code>undefined<\/code>\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-smi\">document<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">all<\/span> <span class=\"pl-k\">instanceof<\/span> <span class=\"pl-v\">Object<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-k\">typeof<\/span> <span class=\"pl-smi\">document<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">all<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'undefined'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u540c\u65f6\uff0c<code>document.all<\/code>\u00a0\u4e0d\u7b49\u4e8e\u00a0<code>undefined<\/code>\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-smi\">document<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">all<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">undefined<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-k\">typeof<\/span> <span class=\"pl-smi\">document<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">all<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'undefined'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4f46\u662f\u540c\u65f6\uff0c<code>document.all<\/code>\u00a0\u4e0d\u7b49\u4e8e\u00a0<code>undefined<\/code>\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-smi\">document<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">all<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">undefined<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-smi\">document<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">all<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4e0d\u8fc7\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-smi\">document<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">all<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-9\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-9\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<blockquote>\n<p dir=\"auto\"><code>document.all<\/code>\u00a0\u4f5c\u4e3a\u8bbf\u95ee\u9875\u9762 DOM \u8282\u70b9\u7684\u4e00\u79cd\u65b9\u5f0f\uff0c\u5728\u65e9\u671f\u7248\u672c\u7684 IE \u6d4f\u89c8\u5668\u4e2d\u8f83\u4e3a\u6d41\u884c\u3002\u5c3d\u7ba1\u8fd9\u4e00 API \u4ece\u672a\u6210\u4e3a\u6807\u51c6\uff0c\u4f46\u88ab\u5e7f\u6cdb\u4f7f\u7528\u5728\u65e9\u671f\u7684 JS \u4ee3\u7801\u4e2d\u3002\u5f53\u6807\u51c6\u6f14\u53d8\u51fa\u65b0\u7684 API\uff08\u4f8b\u5982\u00a0<code>document.getElementById<\/code>\uff09\u65f6\uff0c\u8fd9\u4e2a API \u8c03\u7528\u5c31\u88ab\u5e9f\u5f03\u4e86\u3002\u56e0\u4e3a\u8fd9\u4e2a API \u7684\u4f7f\u7528\u8303\u56f4\u8f83\u4e3a\u5e7f\u6cdb\uff0c\u6807\u51c6\u59d4\u5458\u4f1a\u51b3\u5b9a\u4fdd\u7559\u8fd9\u4e2a API\uff0c\u4f46\u6709\u610f\u5730\u5f15\u5165\u4e00\u4e2a\u8fdd\u53cd JavaScript \u6807\u51c6\u7684\u89c4\u8303\u3002 \u8fd9\u4e2a\u6709\u610f\u7684\u5bf9\u8fdd\u53cd\u6807\u51c6\u7684\u89c4\u8303\u660e\u786e\u5730\u5141\u8bb8\u8be5 API \u4e0e\u00a0<code>undefined<\/code>\u00a0\u4f7f\u7528<a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-strict-equality-comparison\" rel=\"nofollow\">\u4e25\u683c\u76f8\u7b49\u6bd4\u8f83<\/a>\u5f97\u51fa\u00a0<code>false<\/code>\u00a0\u800c\u4f7f\u7528<a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-abstract-equality-comparison\" rel=\"nofollow\">\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83<\/a>\u00a0\u5f97\u51fa\u00a0<code>true<\/code>\u3002<\/p>\n<p dir=\"auto\">\u2014\u00a0<a href=\"https:\/\/html.spec.whatwg.org\/multipage\/obsolete.html#dom-document-all\" rel=\"nofollow\">\u201c\u5e9f\u5f03\u529f\u80fd &#8211; document.all\u201d<\/a>\u00a0at WhatWG &#8211; HTML spec \u2014 YDKJS\uff08\u4f60\u4e0d\u61c2 JS\uff09 &#8211; \u7c7b\u578b\u4e0e\u8bed\u6cd5 \u4e2d\u7684\u00a0<a href=\"https:\/\/github.com\/getify\/You-Dont-Know-JS\/blob\/0d79079b61dad953bbfde817a5893a49f7e889fb\/types%20%26%20grammar\/ch4.md#falsy-objects\">\u201c\u7b2c 4 \u7ae0 &#8211; ToBoolean &#8211; \u5047\u503c<\/a><\/p>\n<\/blockquote>\n<h2 id=\"user-content-\u6700\u5c0f\u503c\u5927\u4e8e\u96f6\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%9C%80%E5%B0%8F%E5%80%BC%E5%A4%A7%E4%BA%8E%E9%9B%B6\">\u6700\u5c0f\u503c\u5927\u4e8e\u96f6<\/a><\/h2>\n<p dir=\"auto\"><code>Number.MIN_VALUE<\/code>\u00a0\u662f\u6700\u5c0f\u7684\u6570\u5b57\uff0c\u5927\u4e8e\u96f6\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-v\">Number<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">MIN_VALUE<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-10\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-10\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<blockquote>\n<p dir=\"auto\"><code>Number.MIN_VALUE<\/code>\u00a0\u662f\u00a0<code>5e-324<\/code>\uff0c\u5373\u53ef\u4ee5\u5728\u6d6e\u70b9\u7cbe\u5ea6\u5185\u8868\u793a\u7684\u6700\u5c0f\u6b63\u6570\uff0c\u4e5f\u662f\u5728\u8be5\u7cbe\u5ea6\u5185\u65e0\u9650\u63a5\u8fd1\u96f6\u7684\u6570\u5b57\u3002\u5b83\u5b9a\u4e49\u4e86\u6d6e\u70b9\u6570\u7684\u6700\u9ad8\u7cbe\u5ea6\u3002<\/p>\n<\/blockquote>\n<blockquote>\n<p dir=\"auto\">\u73b0\u5728\uff0c\u6574\u4f53\u6700\u5c0f\u7684\u503c\u662f\u00a0<code>Number.NEGATIVE_INFINITY<\/code>\uff0c\u5c3d\u7ba1\u8fd9\u5728\u4e25\u683c\u610f\u4e49\u4e0a\u5e76\u4e0d\u662f\u771f\u6b63\u7684\u6570\u5b57\u3002<\/p>\n<p dir=\"auto\">\u2014 StackOverflow \u4e0a\u7684<a href=\"https:\/\/stackoverflow.com\/questions\/26614728\/why-is-0-less-than-number-min-value-in-javascript\" rel=\"nofollow\">\u201c\u4e3a\u4ec0\u4e48\u5728 JavaScript \u4e2d\u00a0<code>0<\/code>\u00a0\u5c0f\u4e8e\u00a0<code>Number.MIN_VALUE<\/code>\uff1f\u201d<\/a><\/p>\n<\/blockquote>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-well-known-symbols\" rel=\"nofollow\"><strong>20.1.2.9<\/strong>\u00a0Number.MIN_VALUE<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u51fd\u6570\u4e0d\u662f\u51fd\u6570\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%87%BD%E6%95%B0%E4%B8%8D%E6%98%AF%E5%87%BD%E6%95%B0\">\u51fd\u6570\u4e0d\u662f\u51fd\u6570<\/a><\/h2>\n<blockquote>\n<p dir=\"auto\">\u26a0\ufe0f\u00a0V8 v5.5 \u6216\u66f4\u4f4e\u7248\u672c\u4e2d\u51fa\u73b0\u7684 Bug\uff08Node.js &lt;= 7\uff09\u00a0\u26a0\ufe0f<\/p>\n<\/blockquote>\n<p dir=\"auto\">\u5927\u5bb6\u90fd\u77e5\u9053\u00a0<em>undefined \u4e0d\u662f function<\/em>\u00a0\u5bf9\u5427\uff1f\u4f46\u662f\u4f60\u77e5\u9053\u8fd9\u4e2a\u5417\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/ \u58f0\u660e\u4e00\u4e2a\u7ee7\u627fnull\u7684\u7c7b<\/span>\r\n<span class=\"pl-k\">class<\/span> <span class=\"pl-v\">Foo<\/span> <span class=\"pl-k\">extends<\/span> <span class=\"pl-c1\">null<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt; [Function: Foo]<\/span>\r\n\r\n<span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Foo<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-k\">instanceof<\/span> <span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ &gt; TypeError: function is not a function<\/span>\r\n<span class=\"pl-c\">\/\/ &gt;     at \u2026 \u2026 \u2026<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-11\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-11\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8fd9\u4e0d\u662f\u89c4\u8303\u7684\u4e00\u90e8\u5206\u3002\u8fd9\u53ea\u662f\u4e00\u4e2a\u7f3a\u9677\uff0c\u4e14\u5df2\u7ecf\u4fee\u590d\u4e86\u3002\u6240\u4ee5\u5c06\u6765\u4e0d\u4f1a\u6709\u8fd9\u4e2a\u95ee\u9898\u3002<\/p>\n<h3 id=\"user-content-super-constructor-null-of-foo-is-not-a-constructor-foo-\u7684\u8d85\u7c7b\u7684\u6784\u9020\u51fd\u6570-null-\u4e0d\u662f\u6784\u9020\u51fd\u6570\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#super-constructor-null-of-foo-is-not-a-constructor-foo-%E7%9A%84%E8%B6%85%E7%B1%BB%E7%9A%84%E6%9E%84%E9%80%A0%E5%87%BD%E6%95%B0-null-%E4%B8%8D%E6%98%AF%E6%9E%84%E9%80%A0%E5%87%BD%E6%95%B0\">Super constructor null of Foo is not a constructor (Foo \u7684\u8d85\u7c7b\u7684\u6784\u9020\u51fd\u6570 null \u4e0d\u662f\u6784\u9020\u51fd\u6570)<\/a><\/h3>\n<p dir=\"auto\">\u8fd9\u662f\u524d\u8ff0\u7f3a\u9677\u7684\u540e\u7eed\u884c\u4e3a\uff0c\u5728\u73b0\u4ee3\u73af\u5883\u4e2d\u53ef\u4ee5\u590d\u73b0\uff08\u5728 Chrome 71 \u548c Node.js v11.8.0 \u6d4b\u8bd5\u6210\u529f\uff09\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">class<\/span> <span class=\"pl-v\">Foo<\/span> <span class=\"pl-k\">extends<\/span> <span class=\"pl-c1\">null<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Foo<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-k\">instanceof<\/span> <span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ &gt; TypeError: Super constructor null of Foo is not a constructor<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-12\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-12\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8fd9\u5e76\u4e0d\u662f\u7f3a\u9677\uff0c\u56e0\u4e3a\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-v\">Object<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">getPrototypeOf<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-v\">Foo<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">prototype<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; null<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u82e5\u5f53\u524d\u7c7b\u6ca1\u6709\u6784\u9020\u51fd\u6570\uff0c\u5219\u5728\u6784\u9020\u8be5\u7c7b\u65f6\u4f1a\u987a\u6b21\u8c03\u7528\u5176\u539f\u578b\u94fe\u4e0a\u7684\u6784\u9020\u51fd\u6570\uff0c\u800c\u672c\u4f8b\u4e2d\u5176\u7236\u7c7b\u6ca1\u6709\u6784\u9020\u51fd\u6570\u3002\u8865\u5145\u4e00\u4e0b\uff0c<code>null<\/code>\u00a0\u4e5f\u662f\u4e00\u4e2a\u00a0<code>object<\/code>\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">typeof<\/span> <span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-s\">\"object\"<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u56e0\u6b64\uff0c\u4f60\u53ef\u4ee5\u7ee7\u627f\u00a0<code>null<\/code>\uff08\u5c3d\u7ba1\u5728\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u7684\u4e16\u754c\u91cc\u8fd9\u662f\u4e0d\u5141\u8bb8\u7684\uff09\uff0c\u4f46\u662f\u5374\u4e0d\u80fd\u8c03\u7528\u00a0<code>null<\/code>\u00a0\u7684\u6784\u9020\u51fd\u6570\u3002\u82e5\u4f60\u628a\u4ee3\u7801\u6539\u6210\u8fd9\u6837\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">class<\/span> <span class=\"pl-v\">Foo<\/span> <span class=\"pl-k\">extends<\/span> <span class=\"pl-c1\">null<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-en\">constructor<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n    <span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"something\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-kos\">}<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u5c06\u4f1a\u62a5\u9519\uff1a<\/p>\n<div class=\"snippet-clipboard-content notranslate position-relative overflow-auto\">\n<pre class=\"notranslate\"><code>ReferenceError: Must call super constructor in derived class before accessing 'this' or returning from derived constructor\r\n\/\/ \u5f15\u7528\u9519\u8bef\uff1a\u5728\u8bbf\u95ee`this`\u6216\u8fd4\u56de\u4e4b\u524d\uff0c\u4f60\u9700\u8981\u5728\u5b50\u7c7b\u4e2d\u5148\u8c03\u7528super\u6784\u9020\u51fd\u6570\r\n<\/code><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4f46\u662f\u5f53\u4f60\u52a0\u4e0a\u00a0<code>super<\/code>\u00a0\u65f6\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">class<\/span> <span class=\"pl-v\">Foo<\/span> <span class=\"pl-k\">extends<\/span> <span class=\"pl-c1\">null<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-en\">constructor<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n    <span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">111<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n    <span class=\"pl-smi\">super<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-kos\">}<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">JS \u629b\u51fa\u9519\u8bef\uff1a<\/p>\n<div class=\"snippet-clipboard-content notranslate position-relative overflow-auto\">\n<pre class=\"notranslate\"><code>TypeError: Super constructor null of Foo is not a constructor\r\n\/\/ \u7c7b\u578b\u9519\u8bef\uff1aFoo\u7684\u8d85\u7c7b\u7684\u6784\u9020\u51fd\u6570null\u4e0d\u662f\u6784\u9020\u51fd\u6570\r\n<\/code><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/github.com\/geekjob\">@geekjob<\/a>\u00a0\u53d1\u5e03\u7684\u00a0<a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/pull\/102#discussion_r259143582\" data-hovercard-type=\"pull_request\" data-hovercard-url=\"\/denysdovhan\/wtfjs\/pull\/102\/hovercard\">\u5bf9\u8be5\u95ee\u9898\u7684\u89e3\u91ca<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u6570\u7ec4\u76f8\u52a0\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%95%B0%E7%BB%84%E7%9B%B8%E5%8A%A0\">\u6570\u7ec4\u76f8\u52a0<\/a><\/h2>\n<p dir=\"auto\">\u5982\u679c\u4f60\u5c1d\u8bd5\u5c06\u4e24\u4e2a\u6570\u7ec4\u76f8\u52a0\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">5<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">6<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; '1,2,34,5,6'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-13\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-13\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u6570\u7ec4\u4e4b\u95f4\u4f1a\u53d1\u751f\u4e32\u8054\u3002\u6b65\u9aa4\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span>\r\n  <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">5<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">6<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">[<\/span>\r\n    <span class=\"pl-c\">\/\/ \u8c03\u7528 toString()<\/span>\r\n    <span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toString<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">+<\/span>\r\n  <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">5<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">6<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toString<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ \u4e32\u8054<\/span>\r\n<span class=\"pl-s\">\"1,2,3\"<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-s\">\"4,5,6\"<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt;<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"1,2,34,5,6\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h1 id=\"user-content-\u6570\u7ec4\u4e2d\u7684\u5c3e\u9017\u53f7\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%95%B0%E7%BB%84%E4%B8%AD%E7%9A%84%E5%B0%BE%E9%80%97%E5%8F%B7\">\u6570\u7ec4\u4e2d\u7684\u5c3e\u9017\u53f7<\/a><\/h1>\n<p dir=\"auto\">\u5047\u8bbe\u4f60\u60f3\u8981\u521b\u5efa\u4e86\u4e00\u4e2a\u5305\u542b 4 \u4e2a\u7a7a\u5143\u7d20\u7684\u6570\u7ec4\u3002\u5982\u4e0b\u6240\u793a\uff0c\u6700\u7ec8\u53ea\u80fd\u5f97\u5230\u4e00\u4e2a\u5305\u542b\u4e09\u4e2a\u5143\u7d20\u7684\u6570\u7ec4\uff0c\u539f\u56e0\u5728\u4e8e\u5c3e\u9017\u53f7\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">let<\/span> <span class=\"pl-s1\">a<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-kos\">,<\/span> <span class=\"pl-kos\">,<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">length<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 3<\/span>\r\n<span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toString<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; ',,'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-14\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-14\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<blockquote>\n<p dir=\"auto\"><strong>\u5c3e\u9017\u53f7<\/strong>\u00a0\uff08trailing commas\uff0c\u6709\u65f6\u4e5f\u79f0\u4e3a\u201c\u6700\u540e\u9017\u53f7\u201d\uff08final commas\uff09\uff09 \u5728\u5411 JavaScript \u4ee3\u7801\u4e2d\u6dfb\u52a0\u65b0\u5143\u7d20\u3001\u53c2\u6570\u6216\u5c5e\u6027\u65f6\u975e\u5e38\u6709\u7528\u3002\u5982\u679c\u60a8\u60f3\u6dfb\u52a0\u4e00\u4e2a\u65b0\u5c5e\u6027\uff0c\u82e5\u524d\u4e00\u884c\u5df2\u7ecf\u6709\u5c3e\u9017\u53f7\uff0c\u4f60\u65e0\u9700\u4fee\u6539\u524d\u4e00\u884c\uff0c\u53ea\u8981\u6dfb\u52a0\u4e00\u4e2a\u65b0\u884c\u5e76\u52a0\u4e0a\u5c3e\u9017\u53f7\u5373\u53ef\u3002\u8fd9\u4f7f\u5f97\u7248\u672c\u63a7\u5236\u5386\u53f2\u8f83\u4e3a\u5e72\u51c0\uff0c\u7f16\u8f91\u4ee3\u7801\u4e5f\u5f88\u7b80\u5355\u3002<\/p>\n<p dir=\"auto\">\u2014 MDN \u4e0a\u7684\u00a0<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Trailing_commas\" rel=\"nofollow\">\u5c3e\u9017\u53f7<\/a><\/p>\n<\/blockquote>\n<h2 id=\"user-content-\u6570\u7ec4\u7684\u76f8\u7b49\u6027\u662f\u6df1\u6c34\u731b\u517d\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%95%B0%E7%BB%84%E7%9A%84%E7%9B%B8%E7%AD%89%E6%80%A7%E6%98%AF%E6%B7%B1%E6%B0%B4%E7%8C%9B%E5%85%BD\">\u6570\u7ec4\u7684\u76f8\u7b49\u6027\u662f\u6df1\u6c34\u731b\u517d<\/a><\/h2>\n<p dir=\"auto\">\u6570\u7ec4\u4e4b\u95f4\u8fdb\u884c\u76f8\u7b49\u6bd4\u8f83\u662f JS \u4e2d\u7684\u6df1\u6c34\u731b\u517d\uff0c\u770b\u770b\u8fd9\u4e9b\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">''<\/span>   <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span>    <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-s\">''<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">''<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span>   <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">''<\/span>  <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-s\">''<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span>  <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">''<\/span>      <span class=\"pl-c\">\/\/ true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span>       <span class=\"pl-c\">\/\/ true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">undefined<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">''<\/span> <span class=\"pl-c\">\/\/ true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">undefined<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span>  <span class=\"pl-c\">\/\/ true<\/span>\r\n\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span>  <span class=\"pl-c\">\/\/ true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">''<\/span> <span class=\"pl-c\">\/\/ true<\/span>\r\n\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">''<\/span> <span class=\"pl-c\">\/\/ true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span>  <span class=\"pl-c\">\/\/ true<\/span>\r\n\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span> <span class=\"pl-c1\">null<\/span> <span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span>  <span class=\"pl-c\">\/\/ true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span> <span class=\"pl-c1\">null<\/span> <span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">''<\/span> <span class=\"pl-c\">\/\/ true<\/span>\r\n\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span> <span class=\"pl-c1\">undefined<\/span> <span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span>  <span class=\"pl-c\">\/\/ true<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span> <span class=\"pl-c1\">undefined<\/span> <span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">''<\/span> <span class=\"pl-c\">\/\/ true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-15\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-15\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u4ed4\u7ec6\u9605\u8bfb\u4e0a\u9762\u7684\u4f8b\u5b50\uff01\u89c4\u8303\u4e2d\u7684\u00a0<a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-abstract-equality-comparison\" rel=\"nofollow\"><strong>7.2.13<\/strong>\u00a0\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83<\/a>\u00a0\u4e00\u8282\u63cf\u8ff0\u4e86\u8fd9\u4e9b\u884c\u4e3a\u3002<\/p>\n<h2 id=\"user-content-undefined-\u548c-number\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#undefined-%E5%92%8C-number\"><code>undefined<\/code>\u00a0\u548c\u00a0<code>Number<\/code><\/a><\/h2>\n<p dir=\"auto\">\u65e0\u53c2\u6570\u8c03\u7528\u00a0<code>Number<\/code>\u00a0\u6784\u9020\u51fd\u6570\u4f1a\u8fd4\u56de\u00a0<code>0<\/code>\u3002\u6211\u4eec\u77e5\u9053\uff0c\u5f53\u51fd\u6570\u6ca1\u6709\u63a5\u53d7\u5230\u6307\u5b9a\u4f4d\u7f6e\u7684\u5b9e\u9645\u53c2\u6570\u65f6\uff0c\u8be5\u5904\u7684\u5f62\u5f0f\u53c2\u6570\u7684\u503c\u4f1a\u662f\u00a0<code>undefined<\/code>\u3002\u56e0\u6b64\uff0c\u4f60\u53ef\u80fd\u89c9\u5f97\u5f53\u6211\u4eec\u4f20\u5165\u00a0<code>undefined<\/code>\u00a0\u65f6\u5e94\u5f53\u540c\u6837\u8fd4\u56de\u00a0<code>0<\/code>\u3002\u7136\u800c\u5b9e\u9645\u4e0a\u4f20\u5165\u00a0<code>undefined<\/code>\u00a0\u8fd4\u56de\u7684\u662f\u00a0<code>NaN<\/code>\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-v\">Number<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 0<\/span>\r\n<span class=\"pl-v\">Number<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">undefined<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; NaN<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-16\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-16\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u6839\u636e\u89c4\u8303\uff1a<\/p>\n<ol dir=\"auto\">\n<li>\u82e5\u65e0\u53c2\u6570\u8c03\u7528\u8be5\u51fd\u6570\uff0c<code>n<\/code>\u00a0\u5c06\u4e3a\u00a0<code>+0<\/code>\u3002<\/li>\n<li>\u5426\u5219\uff0c<code>n<\/code>\u00a0\u5c06\u4e3a\uff1f<code>ToNumber(value)<\/code>\u3002<\/li>\n<li>\u5982\u679c\u503c\u4e3a\u00a0<code>undefined<\/code>\uff0c<code>ToNumber(undefined)<\/code>\u00a0\u5e94\u8be5\u8fd4\u56de\u00a0<code>NaN<\/code>\u3002<\/li>\n<\/ol>\n<p dir=\"auto\">\u8fd9\u662f\u76f8\u5e94\u7684\u90e8\u5206\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-number-constructor\" rel=\"nofollow\"><strong>20.1.1<\/strong>\u00a0Number \u6784\u9020\u51fd\u6570<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-tonumber\" rel=\"nofollow\"><strong>7.1.3<\/strong>\u00a0ToNumber(<code>argument<\/code>)<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-parseint-\u662f\u4e00\u4e2a\u574f\u86cb\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#parseint-%E6%98%AF%E4%B8%80%E4%B8%AA%E5%9D%8F%E8%9B%8B\"><code>parseInt<\/code>\u00a0\u662f\u4e00\u4e2a\u574f\u86cb<\/a><\/h2>\n<p dir=\"auto\"><code>parseInt<\/code>\u00a0\u4ee5\u5b83\u7684\u602a\u5f02\u800c\u51fa\u540d\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"f*ck\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; NaN<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"f*ck\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">16<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 15<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\"><strong>? \u8bf4\u660e\uff1a<\/strong>\u00a0\u8fd9\u662f\u56e0\u4e3a\u00a0<code>parseInt<\/code>\u00a0\u4f1a\u6301\u7eed\u89e3\u6790\u76f4\u5230\u5b83\u89e3\u6790\u5230\u4e00\u4e2a\u4e0d\u8bc6\u522b\u7684\u5b57\u7b26\uff0c<code>'f*ck'<\/code>\u00a0\u4e2d\u7684\u00a0<code>f<\/code>\u00a0\u662f 16 \u8fdb\u5236\u4e0b\u7684\u00a0<code>15<\/code>\u3002<\/p>\n<p dir=\"auto\">\u89e3\u6790\u00a0<code>Infinity<\/code>\u00a0\u5230\u6574\u6570\u4e5f\u5f88\u6709\u610f\u601d\u2026\u2026<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Infinity\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">10<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; NaN<\/span>\r\n<span class=\"pl-c\">\/\/ ...<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Infinity\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">18<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; NaN...<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Infinity\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">19<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 18<\/span>\r\n<span class=\"pl-c\">\/\/ ...<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Infinity\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">23<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 18...<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Infinity\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">24<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 151176378<\/span>\r\n<span class=\"pl-c\">\/\/ ...<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Infinity\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">29<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 385849803<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Infinity\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">30<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 13693557269<\/span>\r\n<span class=\"pl-c\">\/\/ ...<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Infinity\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">34<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 28872273981<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Infinity\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">35<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 1201203301724<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Infinity\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">36<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 1461559270678...<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Infinity\"<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">37<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; NaN<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4e5f\u8981\u5c0f\u5fc3\u89e3\u6790\u00a0<code>null<\/code>\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">24<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 23<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\"><strong>? \u8bf4\u660e\uff1a<\/strong><\/p>\n<blockquote>\n<p dir=\"auto\">\u5b83\u5c06\u00a0<code>null<\/code>\u00a0\u8f6c\u6362\u6210\u5b57\u7b26\u4e32\u00a0<code>'null'<\/code>\uff0c\u5e76\u5c1d\u8bd5\u8f6c\u6362\u5b83\u3002\u5bf9\u4e8e\u57fa\u6570 0 \u5230 23\uff0c\u6ca1\u6709\u53ef\u4ee5\u8f6c\u6362\u7684\u6570\u5b57\uff0c\u56e0\u6b64\u8fd4\u56de NaN\u3002\u800c\u5f53\u57fa\u6570\u4e3a 24 \u65f6\uff0c\u7b2c 14 \u4e2a\u5b57\u6bcd<code>\u201cn\u201d<\/code>\u4e5f\u53ef\u4ee5\u4f5c\u6570\u5b57\u7528\u3002\u5f53\u57fa\u6570\u4e3a 31 \u65f6\uff0c\u7b2c 21 \u4e2a\u5b57\u6bcd<code>\u201cu\u201d<\/code>\u8fdb\u5165\u6570\u5b57\u7684\u884c\u5217\uff0c\u6b64\u65f6\u6574\u4e2a\u5b57\u7b26\u4e32\u90fd\u53ef\u4ee5\u89e3\u6790\u4e86\u3002\u800c\u5f53\u57fa\u6570\u589e\u52a0\u5230 37 \u4ee5\u4e0a\uff0c\u5df2\u7ecf\u8d85\u51fa\u4e86\u6570\u5b57\u548c\u5b57\u6bcd\u6240\u80fd\u8868\u8fbe\u7684\u6570\u5b57\u8303\u56f4\uff0c\u56e0\u6b64\u4e00\u5f8b\u8fd4\u56de\u00a0<code>NaN<\/code>\u3002<\/p>\n<p dir=\"auto\">\u2014 StackOverflow \u4e0a\u7684\u00a0<a href=\"https:\/\/stackoverflow.com\/questions\/6459758\/parseintnull-24-23-wait-what\" rel=\"nofollow\">\u201cparseInt(null, 24) === 23 \u4ec0\u4e48\u9b3c\u201d<\/a><\/p>\n<\/blockquote>\n<p dir=\"auto\">\u4e0d\u8981\u5fd8\u8bb0\u516b\u8fdb\u5236\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"06\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ 6<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"08\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ 8 \u5982\u679c\u652f\u6301 ECMAScript 5<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"08\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ 0 \u5982\u679c\u4e0d\u652f\u6301 ECMAScript 5<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\"><strong>? \u8bf4\u660e\uff1a<\/strong>\u00a0\u5f53\u8f93\u5165\u7684\u5b57\u7b26\u4e32\u4ee5\u201c0\u201d\u5f00\u59cb\u65f6\uff0c\u6839\u636e\u5b9e\u73b0\u7684\u4e0d\u540c\uff0c\u4f1a\u88ab\u89e3\u91ca\u4e3a\u516b\u8fdb\u5236\u6216\u5341\u8fdb\u5236\u3002ECMAScript 5 \u660e\u786e\u8868\u793a\u5e94\u5f53\u4f7f\u7528\u5341\u8fdb\u5236\uff0c\u4f46\u6709\u90e8\u5206\u6d4f\u89c8\u5668\u4ecd\u4e0d\u652f\u6301\u3002\u56e0\u6b64\u63a8\u8350\u5728\u8c03\u7528\u00a0<code>parseInt<\/code>\u00a0\u51fd\u6570\u65f6\u603b\u662f\u4f20\u5165\u8868\u793a\u57fa\u6570\u7684\u7b2c\u4e8c\u4e2a\u53c2\u6570\u3002<\/p>\n<p dir=\"auto\"><code>parseInt<\/code>\u00a0\u4f1a\u5148\u5c06\u53c2\u6570\u503c\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">{<\/span> <span class=\"pl-en\">toString<\/span>: <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-en\">valueOf<\/span>: <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-c1\">1<\/span> <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 2<\/span>\r\n<span class=\"pl-v\">Number<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">{<\/span> <span class=\"pl-en\">toString<\/span>: <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-en\">valueOf<\/span>: <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-c1\">1<\/span> <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 1<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u89e3\u6790\u6d6e\u70b9\u6570\u7684\u65f6\u5019\u8981\u6ce8\u610f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">0.000001<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 0<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">0.0000001<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 1<\/span>\r\n<span class=\"pl-en\">parseInt<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span> <span class=\"pl-c1\">\/<\/span> <span class=\"pl-c1\">1999999<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 5<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\"><strong>? \u8bf4\u660e\uff1a<\/strong>\u00a0<code>parseInt<\/code>\u00a0\u63a5\u53d7\u5b57\u7b26\u4e32\u53c2\u6570\u5e76\u8fd4\u56de\u4e00\u4e2a\u6307\u5b9a\u57fa\u6570\u4e0b\u7684\u6574\u6570\u3002<code>parseInt<\/code>\u00a0\u4f1a\u5c06\u5b57\u7b26\u4e32\u4e2d\u9996\u4e2a\u975e\u6570\u5b57\u5b57\u7b26\uff08\u5b57\u7b26\u96c6\u7531\u57fa\u6570\u51b3\u5b9a\uff09\u53ca\u5176\u540e\u7684\u5185\u5bb9\u5168\u90e8\u622a\u65ad\u3002\u5982\u00a0<code>0.000001<\/code>\u00a0\u88ab\u8f6c\u6362\u4e3a\u00a0<code>\"0.000001\"<\/code>\uff0c\u56e0\u6b64\u00a0<code>parseInt<\/code>\u00a0\u8fd4\u56de\u00a0<code>0<\/code>\u3002\u800c\u00a0<code>0.0000001<\/code>\u00a0\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\u4f1a\u53d8\u6210\u00a0<code>\"1e-7\"<\/code>\uff0c\u56e0\u6b64\u00a0<code>parseInt<\/code>\u00a0\u8fd4\u56de\u00a0<code>1<\/code>\u3002<code>1\/1999999<\/code>\u00a0\u88ab\u8f6c\u6362\u4e3a\u00a0<code>5.00000250000125e-7<\/code>\uff0c\u6240\u4ee5\u00a0<code>parseInt<\/code>\u00a0\u8fd4\u56de\u00a0<code>5<\/code>\u3002<\/p>\n<h2 id=\"user-content-true-\u548c-false-\u7684\u6570\u5b66\u8fd0\u7b97\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#true-%E5%92%8C-false-%E7%9A%84%E6%95%B0%E5%AD%A6%E8%BF%90%E7%AE%97\"><code>true<\/code>\u00a0\u548c\u00a0<code>false<\/code>\u00a0\u7684\u6570\u5b66\u8fd0\u7b97<\/a><\/h2>\n<p dir=\"auto\">\u505a\u4e00\u4e0b\u6570\u5b66\u8ba1\u7b97\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 2<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">*<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">-<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 3<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u55ef\u2026\u2026?<\/p>\n<h3 id=\"user-content--\u8bf4\u660e-17\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-17\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u6211\u4eec\u53ef\u4ee5\u7528\u00a0<code>Number<\/code>\u00a0\u6784\u9020\u51fd\u6570\u5c06\u503c\u5f3a\u5236\u8f6c\u5316\u6210\u6570\u503c\u3002\u5f88\u660e\u663e\uff0c<code>true<\/code>\u00a0\u5c06\u88ab\u5f3a\u5236\u8f6c\u6362\u4e3a\u00a0<code>1<\/code>\u00a0\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-v\">Number<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 1<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4e00\u5143\u52a0\u8fd0\u7b97\u7b26\u4f1a\u5c1d\u8bd5\u5c06\u5176\u503c\u8f6c\u6362\u6210\u6570\u5b57\u3002\u5b83\u53ef\u4ee5\u8f6c\u6362\u5b57\u7b26\u4e32\u5f62\u5f0f\u8868\u8fbe\u7684\u6574\u6570\u548c\u6d6e\u70b9\u6570\uff0c\u4ee5\u53ca\u975e\u5b57\u7b26\u4e32\u503c\u00a0<code>true<\/code>\u3001<code>false<\/code>\u00a0\u548c\u00a0<code>null<\/code>\u3002\u5982\u679c\u5b83\u4e0d\u80fd\u89e3\u6790\u7279\u5b9a\u7684\u503c\uff0c\u5b83\u5c06\u8f6c\u5316\u4e3a\u00a0<code>NaN<\/code>\u3002\u8fd9\u610f\u5473\u7740\u6211\u4eec\u53ef\u4ee5\u6709\u66f4\u7b80\u4fbf\u7684\u65b9\u5f0f\u5c06\u00a0<code>true<\/code>\u00a0\u8f6c\u6362\u6210\u00a0<code>1<\/code>\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 1<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u5f53\u4f60\u6267\u884c\u52a0\u6cd5\u6216\u4e58\u6cd5\u65f6\uff0c\u5c06\u4f1a\u00a0<code>ToNumber<\/code>\u00a0\u65b9\u6cd5\u3002\u6839\u636e\u89c4\u8303\uff0c\u8be5\u65b9\u6cd5\u7684\u8fd4\u56de\u503c\u4e3a\uff1a<\/p>\n<blockquote>\n<p dir=\"auto\">\u5982\u679c<code>\u53c2\u6570<\/code>\u662f\u00a0<strong>true<\/strong>\uff0c\u8fd4\u56de\u00a0<strong>1<\/strong>\u3002\u5982\u679c<code>\u53c2\u6570<\/code>\u662f\u00a0<strong>false<\/strong>\uff0c\u5219\u8fd4\u56de\u00a0<strong>+0<\/strong>\u3002<\/p>\n<\/blockquote>\n<p dir=\"auto\">\u56e0\u6b64\u6211\u4eec\u53ef\u4ee5\u5c06\u5e03\u5c14\u503c\u76f8\u52a0\u5e76\u5f97\u5230\u6b63\u786e\u7684\u7ed3\u679c<\/p>\n<p dir=\"auto\">\u76f8\u5e94\u7ae0\u8282\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-unary-plus-operator\" rel=\"nofollow\"><strong>12.5.6<\/strong>\u00a0\u4e00\u5143\u00a0<code>+<\/code>\u00a0\u8fd0\u7b97\u7b26<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-addition-operator-plus\" rel=\"nofollow\"><strong>12.8.3<\/strong>\u00a0\u52a0\u6cd5\u8fd0\u7b97\u7b26\uff08<code>+<\/code>\uff09<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-tonumber\" rel=\"nofollow\"><strong>7.1.3<\/strong>\u00a0ToNumber(<code>argument<\/code>)<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-html-\u6ce8\u91ca\u5728-javascript-\u4e2d\u6709\u6548\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#html-%E6%B3%A8%E9%87%8A%E5%9C%A8-javascript-%E4%B8%AD%E6%9C%89%E6%95%88\">HTML \u6ce8\u91ca\u5728 JavaScript \u4e2d\u6709\u6548<\/a><\/h2>\n<p dir=\"auto\">\u4f60\u53ef\u80fd\u4f1a\u611f\u5230\u9707\u60ca\uff0c<code>&lt;!--<\/code>\u00a0(\u8fd9\u662f HTML \u6ce8\u91ca\u683c\u5f0f\uff09\u4e5f\u662f\u4e00\u4e2a\u6709\u6548\u7684 JavaScript \u6ce8\u91ca\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/ \u6709\u6548\u6ce8\u91ca<\/span>\r\n<span class=\"pl-c1\">&lt;<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">--<\/span> <span class=\"pl-s1\">\u4e5f\u662f\u6709\u6548\u7684\u6ce8\u91ca<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-18\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-18\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u9707\u60ca\u5417\uff1f\u7c7b HTML \u6ce8\u91ca\u65e8\u5728\u5bb9\u8bb8\u4e0d\u7406\u89e3\u00a0<code>&lt;script&gt;<\/code>\u00a0\u6807\u7b7e\u7684\u6d4f\u89c8\u5668\u4f18\u96c5\u964d\u7ea7\u3002\u8fd9\u4e9b\u6d4f\u89c8\u5668\uff0c\u4f8b\u5982 Netscape 1.x \u5df2\u7ecf\u4e0d\u518d\u6d41\u884c\u3002\u56e0\u6b64\uff0c\u5728\u811a\u672c\u6807\u8bb0\u4e2d\u6dfb\u52a0 HTML \u6ce8\u91ca\u662f\u6ca1\u6709\u610f\u4e49\u7684\u3002<\/p>\n<p dir=\"auto\">\u7531\u4e8e Node.js \u57fa\u4e8e V8 \u5f15\u64ce\uff0cNode.js \u8fd0\u884c\u65f6\u4e5f\u652f\u6301\u7c7b\u4f3c HTML \u7684\u6ce8\u91ca\u3002\u800c\u4e14\uff0c\u5b83\u4eec\u662f\u89c4\u8303\u7684\u4e00\u90e8\u5206\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-html-like-comments\" rel=\"nofollow\"><strong>B.1.3<\/strong>\u00a0\u7c7b HTML \u6ce8\u91ca<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-nan-\u4e0d\u662f\u4e00\u4e2a\u6570\u503c\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#nan-%E4%B8%8D%E6%98%AF%E4%B8%80%E4%B8%AA%E6%95%B0%E5%80%BC\"><code>NaN<\/code>\u00a0<del>\u4e0d\u662f<\/del>\u4e00\u4e2a\u6570\u503c<\/a><\/h2>\n<p dir=\"auto\"><code>NaN<\/code>\u00a0\u7c7b\u578b\u662f\u00a0<code>'number'<\/code>\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">typeof<\/span> <span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'number'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-19\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-19\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\"><code>typeof<\/code>\u00a0\u548c\u00a0<code>instanceof<\/code>\u00a0\u8fd0\u7b97\u7b26\u7684\u5de5\u4f5c\u539f\u7406\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-typeof-operator\" rel=\"nofollow\"><strong>12.5.5<\/strong>\u00a0<code>typeof<\/code>\u00a0\u64cd\u4f5c\u7b26<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-instanceofoperator\" rel=\"nofollow\"><strong>12.10.4<\/strong>\u00a0\u8fd0\u884c\u65f6\u8bed\u6cd5\uff1aInstanceofOperator(<code>O<\/code>,<code>C<\/code>)<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content--\u548c-null-\u662f\u5bf9\u8c61\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E5%92%8C-null-%E6%98%AF%E5%AF%B9%E8%B1%A1\"><code>[]<\/code>\u00a0\u548c\u00a0<code>null<\/code>\u00a0\u662f\u5bf9\u8c61<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">typeof<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'object'<\/span>\r\n<span class=\"pl-k\">typeof<\/span> <span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'object'<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ \u7136\u800c<\/span>\r\n<span class=\"pl-c1\">null<\/span> <span class=\"pl-k\">instanceof<\/span> <span class=\"pl-v\">Object<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-20\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-20\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\"><code>typeof<\/code>\u00a0\u8fd0\u7b97\u7b26\u7684\u884c\u4e3a\u5728\u672c\u8282\u7684\u89c4\u8303\u4e2d\u5b9a\u4e49\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/262.ecma-international.org\/12.0\/#sec-typeof-operator\" rel=\"nofollow\"><strong>13.5.3<\/strong>\u00a0<code>typeof<\/code>\u00a0\u64cd\u4f5c\u7b26<\/a><\/li>\n<\/ul>\n<p dir=\"auto\">\u6839\u636e\u89c4\u8303\uff0c<code>typeof<\/code>\u00a0\u64cd\u4f5c\u7b26\u8fd4\u56de\u4e00\u4e2a\u5b57\u7b26\u4e32\uff0c\u4e14\u5fc5\u987b\u7b26\u5408\u00a0<a href=\"https:\/\/262.ecma-international.org\/12.0\/#table-typeof-operator-results\" rel=\"nofollow\">Table 37:\u00a0<code>typeof<\/code>\u00a0\u64cd\u4f5c\u7b26 \u8fd4\u56de\u503c<\/a>\u3002\u5bf9\u4e8e\u6ca1\u6709\u5b9e\u73b0\u00a0<code>[[Call]]<\/code>\u00a0\u7684\u00a0<code>null<\/code>\u3001\u666e\u901a\u5bf9\u8c61\u3001\u6807\u51c6\u7279\u5f02\u5bf9\u8c61\u548c\u975e\u6807\u51c6\u7279\u5f02\u5bf9\u8c61\uff0c\u5b83\u8fd4\u56de\u5b57\u7b26\u4e32\u00a0<code>\"object\u201c<\/code>\u3002<\/p>\n<p dir=\"auto\">\u4f46\u662f\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528\u00a0<code>toString<\/code>\u00a0\u65b9\u6cd5\u68c0\u67e5\u5bf9\u8c61\u7684\u7c7b\u578b\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-v\">Object<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">prototype<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">toString<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">call<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt; '[object Array]'<\/span>\r\n\r\n<span class=\"pl-v\">Object<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">prototype<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">toString<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">call<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Date<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt; '[object Date]'<\/span>\r\n\r\n<span class=\"pl-v\">Object<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">prototype<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">toString<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">call<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt; '[object Null]'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h2 id=\"user-content-\u795e\u5947\u7684\u6570\u5b57\u589e\u957f\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%A5%9E%E5%A5%87%E7%9A%84%E6%95%B0%E5%AD%97%E5%A2%9E%E9%95%BF\">\u795e\u5947\u7684\u6570\u5b57\u589e\u957f<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">999999999999999<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 999999999999999<\/span>\r\n<span class=\"pl-c1\">9999999999999999<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 10000000000000000<\/span>\r\n\r\n<span class=\"pl-c1\">10000000000000000<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 10000000000000000<\/span>\r\n<span class=\"pl-c1\">10000000000000000<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 10000000000000000<\/span>\r\n<span class=\"pl-c1\">10000000000000000<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">1.1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 10000000000000002<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-21\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-21\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8fd9\u662f\u7531 IEEE 754-2008 \u4e8c\u8fdb\u5236\u6d6e\u70b9\u8fd0\u7b97\u6807\u51c6\u5f15\u8d77\u7684\u3002\u6781\u5927\u7684\u6570\u5b57\u4f1a\u88ab\u56db\u820d\u4e94\u5165\u5230\u6700\u8fd1\u7684\u5076\u6570\u3002\u9605\u8bfb\u66f4\u591a\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-ecmascript-language-types-number-type\" rel=\"nofollow\"><strong>6.1.6<\/strong>\u00a0\u6570\u5b57\u7c7b\u578b<\/a><\/li>\n<li>\u7ef4\u57fa\u767e\u79d1\u4e0a\u7684\u00a0<a href=\"https:\/\/en.m.wikipedia.org\/wiki\/IEEE_754\" rel=\"nofollow\">IEEE 754<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-01--02-\u7cbe\u5ea6\u8ba1\u7b97\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#01--02-%E7%B2%BE%E5%BA%A6%E8%AE%A1%E7%AE%97\"><code>0.1 + 0.2<\/code>\u00a0\u7cbe\u5ea6\u8ba1\u7b97<\/a><\/h2>\n<p dir=\"auto\">\u6765\u81ea JavaScript \u7684\u77e5\u540d\u7b11\u8bdd\u3002<code>0.1<\/code>\u00a0\u548c\u00a0<code>0.2<\/code>\u00a0\u76f8\u52a0\u662f\u5b58\u5728\u7cbe\u5ea6\u9519\u8bef\u7684<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">0.1<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">0.2<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 0.30000000000000004<\/span>\r\n<span class=\"pl-c1\">0.1<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">0.2<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">0.3<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-22\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-22\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u6765\u81ea\u4e8e StackOverflow \u4e0a\u7684\u95ee\u9898<a href=\"https:\/\/stackoverflow.com\/questions\/588004\/is-floating-point-math-broken\" rel=\"nofollow\">\u201c\u6d6e\u70b9\u8ba1\u7b97\u574f\u4e86\uff1f\u201d<\/a>\u7684\u7b54\u6848\uff1a<\/p>\n<blockquote>\n<p dir=\"auto\">\u7a0b\u5e8f\u4e2d\u7684\u5e38\u91cf\u00a0<code>0.2<\/code>\u00a0\u548c\u00a0<code>0.3<\/code>\u00a0\u662f\u6700\u63a5\u8fd1\u771f\u5b9e\u503c\u7684\u8fd1\u4f3c\u503c\u3002\u6700\u63a5\u8fd1\u00a0<code>0.2<\/code>\u00a0\u7684\u00a0<code>double<\/code>\u00a0\u5927\u4e8e\u6709\u7406\u6570\u00a0<code>0.2<\/code>\uff0c\u4f46\u6700\u63a5\u8fd1\u00a0<code>0.3<\/code>\u00a0\u7684\u00a0<code>double<\/code>\u00a0\u5c0f\u4e8e\u6709\u7406\u6570\u00a0<code>0.3<\/code>\u3002<code>0.1<\/code>\u00a0\u548c\u00a0<code>0.2<\/code>\u00a0\u7684\u548c\u5927\u4e8e\u6709\u7406\u6570\u00a0<code>0.3<\/code>\uff0c\u56e0\u6b64\u5728\u7a0b\u5e8f\u4e2d\u8fdb\u884c\u5e38\u91cf\u6bd4\u8f83\u4f1a\u5f97\u5230\u5047\u3002<\/p>\n<\/blockquote>\n<p dir=\"auto\">\u8fd9\u4e2a\u95ee\u9898\u592a\u8fc7\u4e8e\u51fa\u540d\uff0c\u751a\u81f3\u6709\u4e00\u4e2a\u7f51\u7ad9\u53eb\u00a0<a href=\"http:\/\/0.30000000000000004.com\/\" rel=\"nofollow\">0.30000000000000004.com<\/a>\u3002\u8fd9\u4e0d\u4ec5\u4ec5\u662f JavaScript \u7279\u6709\u7684\u95ee\u9898\uff0c\u5728\u5176\u4ed6\u91c7\u7528\u6d6e\u70b9\u8ba1\u7b97\u7684\u8bed\u8a00\u4e2d\u4e5f\u5e7f\u6cdb\u5b58\u5728\u3002<\/p>\n<h2 id=\"user-content-\u6269\u5c55\u6570\u5b57\u7684\u65b9\u6cd5\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%89%A9%E5%B1%95%E6%95%B0%E5%AD%97%E7%9A%84%E6%96%B9%E6%B3%95\">\u6269\u5c55\u6570\u5b57\u7684\u65b9\u6cd5<\/a><\/h2>\n<p dir=\"auto\">\u4f60\u53ef\u4ee5\u5411\u5305\u88c5\u5bf9\u8c61\u6dfb\u52a0\u81ea\u5df1\u7684\u65b9\u6cd5\uff0c\u6bd4\u5982\u00a0<code>Number<\/code>\u00a0\u6216\u00a0<code>String<\/code>\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-v\">Number<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">prototype<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">isOne<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-k\">return<\/span> <span class=\"pl-v\">Number<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-smi\">this<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1.0<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">isOne<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">isOne<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">2.0<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">isOne<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">7<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">isOne<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-23\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-23\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u663e\u7136\uff0c\u5728 JavaScript \u4e2d\u6269\u5c55\u00a0<code>Number<\/code>\u00a0\u5bf9\u8c61\u548c\u6269\u5c55\u5176\u4ed6\u5bf9\u8c61\u5e76\u65e0\u4e0d\u540c\u4e4b\u5904\u3002\u4f46\u662f\uff0c\u6269\u5c55\u4e0d\u7b26\u5408\u89c4\u8303\u7684\u51fd\u6570\u884c\u4e3a\u662f\u4e0d\u63a8\u8350\u7684\u3002\u4ee5\u4e0b\u662f\u00a0<code>Number<\/code>\u00a0\u5c5e\u6027\u7684\u5217\u8868\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-number-objects\" rel=\"nofollow\"><strong>20.1<\/strong>\u00a0Number \u5bf9\u8c61<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u4e09\u4e2a\u6570\u5b57\u7684\u6bd4\u8f83\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E4%B8%89%E4%B8%AA%E6%95%B0%E5%AD%97%E7%9A%84%E6%AF%94%E8%BE%83\">\u4e09\u4e2a\u6570\u5b57\u7684\u6bd4\u8f83<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">1<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-c1\">2<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-c1\">3<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">2<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-24\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-24\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u4e3a\u4ec0\u4e48\u4f1a\u8fd9\u6837\u5462\uff1f\u5176\u5b9e\u95ee\u9898\u5728\u4e8e\u8868\u8fbe\u5f0f\u7684\u7b2c\u4e00\u90e8\u5206\u3002\u4ee5\u4e0b\u662f\u5b83\u7684\u5de5\u4f5c\u539f\u7406\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">1<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-c1\">2<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ 1 &lt; 2 -&gt; true<\/span>\r\n<span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ true -&gt; 1<\/span>\r\n<span class=\"pl-c1\">1<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n\r\n<span class=\"pl-c1\">3<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">2<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ 3 &gt; 2 -&gt; true<\/span>\r\n<span class=\"pl-c1\">true<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ true -&gt; 1<\/span>\r\n<span class=\"pl-c1\">1<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u6211\u4eec\u53ef\u4ee5\u7528\u00a0<em>\u5927\u4e8e\u6216\u7b49\u4e8e\u8fd0\u7b97\u7b26\uff08<code>&gt;=<\/code>\uff09<\/em>\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">3<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">2<\/span> <span class=\"pl-c1\">&gt;=<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u8be6\u7ec6\u4e86\u89e3\u89c4\u8303\u4e2d\u7684\u5173\u7cfb\u8fd0\u7b97\u7b26\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-relational-operators\" rel=\"nofollow\"><strong>12.10<\/strong>\u00a0\u5173\u7cfb\u64cd\u4f5c\u7b26<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u6709\u8da3\u7684\u6570\u5b66\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%9C%89%E8%B6%A3%E7%9A%84%E6%95%B0%E5%AD%A6\">\u6709\u8da3\u7684\u6570\u5b66<\/a><\/h2>\n<p dir=\"auto\">\u901a\u5e38 JavaScript \u4e2d\u7684\u7b97\u672f\u8fd0\u7b97\u7684\u7ed3\u679c\u53ef\u80fd\u662f\u975e\u5e38\u96be\u4ee5\u9884\u6599\u7684\u3002 \u8003\u8651\u8fd9\u4e9b\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre> <span class=\"pl-c1\">3<\/span>  <span class=\"pl-c1\">-<\/span> <span class=\"pl-c1\">1<\/span>  <span class=\"pl-c\">\/\/ -&gt; 2<\/span>\r\n <span class=\"pl-c1\">3<\/span>  <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">1<\/span>  <span class=\"pl-c\">\/\/ -&gt; 4<\/span>\r\n<span class=\"pl-s\">'3'<\/span> <span class=\"pl-c1\">-<\/span> <span class=\"pl-c1\">1<\/span>  <span class=\"pl-c\">\/\/ -&gt; 2<\/span>\r\n<span class=\"pl-s\">'3'<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">1<\/span>  <span class=\"pl-c\">\/\/ -&gt; '31'<\/span>\r\n\r\n<span class=\"pl-s\">''<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-s\">''<\/span> <span class=\"pl-c\">\/\/ -&gt; ''<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c\">\/\/ -&gt; ''<\/span>\r\n<span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c\">\/\/ -&gt; 0<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span> <span class=\"pl-c\">\/\/ -&gt; '[object Object]'<\/span>\r\n<span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span> <span class=\"pl-c\">\/\/ -&gt; '[object Object][object Object]'<\/span>\r\n\r\n<span class=\"pl-s\">'222'<\/span> <span class=\"pl-c1\">-<\/span> <span class=\"pl-c1\">-<\/span><span class=\"pl-s\">'111'<\/span> <span class=\"pl-c\">\/\/ -&gt; 333<\/span>\r\n\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">*<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">]<\/span>       <span class=\"pl-c\">\/\/ -&gt; 16<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">*<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span>         <span class=\"pl-c\">\/\/ -&gt; 0<\/span>\r\n<span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">*<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c\">\/\/ NaN<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-25\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-25\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u524d\u56db\u4e2a\u4f8b\u5b50\u53d1\u751f\u4e86\u4ec0\u4e48\uff1f\u4f60\u53ef\u4ee5\u53c2\u8003\u6b64\u5904\u7684\u7ed9\u51fa\u7684\u5173\u4e8e JavaScript \u4e2d\u7684\u52a0\u6cd5\u7684\u5bf9\u7167\u8868\uff1a<\/p>\n<div class=\"snippet-clipboard-content notranslate position-relative overflow-auto\">\n<pre class=\"notranslate\"><code>Number  + Number  -&gt; \u52a0\u6cd5\r\nBoolean + Number  -&gt; \u52a0\u6cd5\r\nBoolean + Boolean -&gt; \u52a0\u6cd5\r\nNumber  + String  -&gt; \u4e32\u8054\u5b57\u7b26\u4e32\r\nString  + Boolean -&gt; \u4e32\u8054\u5b57\u7b26\u4e32\r\nString  + String  -&gt; \u4e32\u8054\u5b57\u7b26\u4e32\r\n<\/code><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u90a3\u5176\u4ed6\u4f8b\u5b50\u5462\uff1f\u5728\u76f8\u52a0\u4e4b\u524d\uff0c<code>[]<\/code>\u00a0\u548c\u00a0<code>{}<\/code>\u00a0\u9690\u5f0f\u8c03\u7528\u00a0<code>ToPrimitive<\/code>\u00a0\u548c\u00a0<code>ToString<\/code>\u00a0\u65b9\u6cd5\u3002\u8be6\u7ec6\u4e86\u89e3\u89c4\u8303\u4e2d\u7684\u6c42\u503c\u8fc7\u7a0b\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-addition-operator-plus\" rel=\"nofollow\"><strong>12.8.3<\/strong>\u00a0\u52a0\u6cd5\u64cd\u4f5c\u7b26 (<code>+<\/code>)<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-toprimitive\" rel=\"nofollow\"><strong>7.1.1<\/strong>\u00a0ToPrimitive(<code>input<\/code>\u00a0[,<code>PreferredType<\/code>])<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-tostring\" rel=\"nofollow\"><strong>7.1.12<\/strong>\u00a0ToString(<code>argument<\/code>)<\/a><\/li>\n<\/ul>\n<p dir=\"auto\">\u4e0d\u8fc7\u9700\u8981\u6ce8\u610f\u6b64\u5904\u7684\u00a0<code>{} + []<\/code>\uff0c\u8fd9\u662f\u4e00\u4e2a\u4f8b\u5916\u3002\u4f60\u53ef\u4ee5\u53d1\u73b0\u5b83\u7684\u6c42\u503c\u7ed3\u679c\u4e0e\u00a0<code>[] + {}<\/code>\u00a0\u4e0d\u540c\uff0c\u8fd9\u662f\u56e0\u4e3a\u5f53\u6211\u4eec\u4e0d\u52a0\u62ec\u53f7\u65f6\uff0c\u5b83\u88ab\u5f53\u4f5c\u662f\u4e00\u4e2a\u7a7a\u7684\u4ee3\u7801\u5757\u548c\u4e00\u4e2a\u4e00\u5143\u52a0\u6cd5\u8fd0\u7b97\u7b26\uff0c\u8fd9\u4e2a\u8fd0\u7b97\u7b26\u4f1a\u628a\u5176\u540e\u7684\u00a0<code>[]<\/code>\u00a0\u8f6c\u6362\u4e3a\u6570\u5b57\u3002\u5177\u4f53\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-c\">\/\/ \u4ee3\u7801\u5757<\/span>\r\n<span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-c1\">+<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 0<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u5f53\u6211\u4eec\u52a0\u4e0a\u62ec\u53f7\uff0c\u60c5\u51b5\u5c31\u4e0d\u4e00\u6837\u4e86\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; [object Object]<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h2 id=\"user-content-\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u52a0\u6cd5\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F%E7%9A%84%E5%8A%A0%E6%B3%95\">\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u52a0\u6cd5<\/a><\/h2>\n<p dir=\"auto\">\u4f60\u77e5\u9053\u53ef\u4ee5\u505a\u8fd9\u6837\u7684\u8fd0\u7b97\u5417\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/ Patch a toString method<\/span>\r\n<span class=\"pl-v\">RegExp<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">prototype<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">toString<\/span> <span class=\"pl-c1\">=<\/span>\r\n  <span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-smi\">this<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">source<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-kos\">}<\/span> <span class=\"pl-c1\">\/<\/span>\r\n  <span class=\"pl-c1\">7<\/span> <span class=\"pl-c1\">\/<\/span>\r\n  <span class=\"pl-c1\">-<\/span><span class=\"pl-pds\"><span class=\"pl-c1\">\/<\/span>5<span class=\"pl-c1\">\/<\/span><\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 2<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-26\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-26\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-get-regexp.prototype.source\" rel=\"nofollow\"><strong>21.2.5.10<\/strong>\u00a0get RegExp.prototype.source<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u5b57\u7b26\u4e32\u4e0d\u662f-string-\u7684\u5b9e\u4f8b\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%AD%97%E7%AC%A6%E4%B8%B2%E4%B8%8D%E6%98%AF-string-%E7%9A%84%E5%AE%9E%E4%BE%8B\">\u5b57\u7b26\u4e32\u4e0d\u662f\u00a0<code>String<\/code>\u00a0\u7684\u5b9e\u4f8b<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-s\">\"str\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'str'<\/span>\r\n<span class=\"pl-k\">typeof<\/span> <span class=\"pl-s\">\"str\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'string'<\/span>\r\n<span class=\"pl-s\">\"str\"<\/span> <span class=\"pl-k\">instanceof<\/span> <span class=\"pl-v\">String<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-27\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-27\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\"><code>String<\/code>\u00a0\u6784\u9020\u51fd\u6570\u8fd4\u56de\u4e00\u4e2a\u5b57\u7b26\u4e32\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">typeof<\/span> <span class=\"pl-v\">String<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"str\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'string'<\/span>\r\n<span class=\"pl-v\">String<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"str\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'str'<\/span>\r\n<span class=\"pl-v\">String<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"str\"<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">\"str\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u518d\u8bd5\u8bd5\u00a0<code>new<\/code>\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">new<\/span> <span class=\"pl-v\">String<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"str\"<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">\"str\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-k\">typeof<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-v\">String<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"str\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'object'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u5bf9\u8c61\uff1f\u5565\u73a9\u610f\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">new<\/span> <span class=\"pl-v\">String<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"str\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; [String: 'str']<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u6709\u5173\u89c4\u8303\u4e2d\u7684 String \u6784\u9020\u51fd\u6570\u7684\u66f4\u591a\u4fe1\u606f\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-string-constructor\" rel=\"nofollow\"><strong>21.1.1<\/strong>\u00a0String \u6784\u9020\u51fd\u6570<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u7528\u53cd\u5f15\u53f7\u8c03\u7528\u51fd\u6570\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%94%A8%E5%8F%8D%E5%BC%95%E5%8F%B7%E8%B0%83%E7%94%A8%E5%87%BD%E6%95%B0\">\u7528\u53cd\u5f15\u53f7\u8c03\u7528\u51fd\u6570<\/a><\/h2>\n<p dir=\"auto\">\u6211\u4eec\u6765\u58f0\u660e\u4e00\u4e2a\u8fd4\u56de\u6240\u6709\u53c2\u6570\u7684\u51fd\u6570\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">function<\/span> <span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span>...<span class=\"pl-s1\">args<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">args<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4f60\u80af\u5b9a\u77e5\u9053\u8c03\u7528\u8fd9\u4e2a\u51fd\u6570\u7684\u65b9\u5f0f\u5e94\u5f53\u662f\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; [ 1, 2, 3 ]<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4f46\u662f\u4f60\u77e5\u9053\u4f60\u8fd8\u53ef\u4ee5\u4f7f\u7528\u53cd\u5f15\u53f7\u8c03\u7528\u4efb\u610f\u51fd\u6570\u5417\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">f<\/span><span class=\"pl-s\">`true is <span class=\"pl-s1\"><span class=\"pl-kos\">${<\/span><span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">}<\/span><\/span>, false is <span class=\"pl-s1\"><span class=\"pl-kos\">${<\/span><span class=\"pl-c1\">false<\/span><span class=\"pl-kos\">}<\/span><\/span>, array is <span class=\"pl-s1\"><span class=\"pl-kos\">${<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">}<\/span><\/span>`<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt; [ [ 'true is ', ', false is ', ', array is ', '' ],<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt;   true,<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt;   false,<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt;   [ 1, 2, 3 ] ]<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-28\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-28\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u5176\u5b9e\uff0c\u5982\u679c\u4f60\u719f\u6089\u00a0<em>\u6807\u7b7e\u6a21\u677f\u5b57\u9762\u91cf<\/em>\uff0c\u4f60\u4f1a\u77e5\u9053\u8fd9\u4e0d\u662f\u4ec0\u4e48\u9b54\u6cd5\u3002\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c<code>f<\/code>\u00a0\u51fd\u6570\u662f\u6a21\u677f\u5b57\u9762\u91cf\u7684\u6807\u7b7e\u3002\u4f60\u53ef\u4ee5\u5b9a\u4e49\u8fd9\u4e2a\u6807\u7b7e\u4ee5\u4f7f\u7528\u51fd\u6570\u89e3\u6790\u6a21\u677f\u6587\u5b57\u3002\u6807\u7b7e\u51fd\u6570\u7684\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f\u5305\u542b\u5b57\u7b26\u4e32\u7684\u6570\u7ec4\uff0c\u5269\u4f59\u7684\u53c2\u6570\u4e0e\u8868\u8fbe\u5f0f\u6709\u5173\u3002\u4f8b\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">function<\/span> <span class=\"pl-en\">template<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">strings<\/span><span class=\"pl-kos\">,<\/span> ...<span class=\"pl-s1\">keys<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-c\">\/\/ \u64cd\u4f5c\u5b57\u7b26\u4e32\u548c\u952e\u503c<\/span>\r\n<span class=\"pl-kos\">}<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u8fd9\u4e5f\u662f\u5728 React \u793e\u533a\u5f88\u6d41\u884c\u7684\u5e93<a href=\"https:\/\/www.styled-components.com\/\" rel=\"nofollow\">? styled-components<\/a>\u7684<a href=\"http:\/\/mxstbr.blog\/2016\/11\/styled-components-magic-explained\/\" rel=\"nofollow\">\u80cc\u540e\u7684\u79d8\u5bc6<\/a>\u3002<\/p>\n<p dir=\"auto\">\u89c4\u8303\u7684\u94fe\u63a5\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-tagged-templates\" rel=\"nofollow\"><strong>12.3.7<\/strong>\u00a0\u6807\u7b7e\u6a21\u677f<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u5230\u5e95-call-\u4e86\u8c01\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%88%B0%E5%BA%95-call-%E4%BA%86%E8%B0%81\">\u5230\u5e95 call \u4e86\u8c01<\/a><\/h2>\n<blockquote>\n<p dir=\"auto\">\u7531\u00a0<a href=\"http:\/\/twitter.com\/cramforce\" rel=\"nofollow\">@cramforce<\/a>\u00a0\u53d1\u73b0<\/p>\n<\/blockquote>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">log<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">call<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">call<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">call<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">call<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">call<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">apply<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">a<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-29\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-29\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u6ce8\u610f\uff0c\u8fd9\u53ef\u80fd\u4f1a\u51fb\u788e\u4f60\u7684\u4e09\u89c2\uff01\u5c1d\u8bd5\u5728\u60a8\u7684\u5934\u8111\u4e2d\u91cd\u73b0\u6b64\u4ee3\u7801\uff1a\u6211\u4eec\u4f7f\u7528\u00a0<code>apply<\/code>\u00a0\u65b9\u6cd5\u8c03\u7528\u00a0<code>call<\/code>\u00a0\u65b9\u6cd5\u3002\u9605\u8bfb\u66f4\u591a\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-function.prototype.call\" rel=\"nofollow\"><strong>19.2.3.3<\/strong>\u00a0Function.prototype.call(<code>thisArg<\/code>, &#8230;<code>args<\/code>)<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-function.prototype.apply\" rel=\"nofollow\">**19.2.3.1 ** Function.prototype.apply(<code>thisArg<\/code>,\u00a0<code>argArray<\/code>)<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-constructor-\u5c5e\u6027\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#constructor-%E5%B1%9E%E6%80%A7\"><code>constructor<\/code>\u00a0\u5c5e\u6027<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">c<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"constructor\"<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">'console.log(\"WTF?\")'<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ &gt; WTF?<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-30\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-30\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8ba9\u6211\u4eec\u9010\u6b65\u5206\u89e3\u8fd9\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/ \u58f0\u660e\u4e00\u4e2a\u65b0\u7684\u5e38\u91cf\u5b57\u7b26\u4e32 'constructor'<\/span>\r\n<span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">c<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"constructor\"<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ c \u662f\u4e00\u4e2a\u5b57\u7b26\u4e32<\/span>\r\n<span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'constructor'<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ \u83b7\u53d6\u5b57\u7b26\u4e32\u7684\u6784\u9020\u51fd\u6570<\/span>\r\n<span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; [Function: String]<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ \u83b7\u53d6\u6784\u9020\u51fd\u6570\u7684\u6784\u9020\u51fd\u6570<\/span>\r\n<span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; [Function: Function]<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ \u8c03\u7528\u51fd\u6570\u6784\u9020\u51fd\u6570\u5e76\u5c06\u65b0\u51fd\u6570\u7684\u4e3b\u4f53\u4f5c\u4e3a\u53c2\u6570\u4f20\u9012<\/span>\r\n<span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">'console.log(\"WTF?\")'<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; [Function: anonymous]<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ \u7136\u540e\u8c03\u7528\u8fd9\u4e2a\u533f\u540d\u51fd\u6570\u5f97\u5230\u7684\u7ed3\u679c\u662f\u4e00\u4e2a\u5b57\u7b26\u4e32 'WTF'<\/span>\r\n<span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">c<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">'console.log(\"WTF?\")'<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ &gt; WTF<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\"><code>Object.prototype.constructor<\/code>\u00a0\u8fd4\u56de\u4e00\u4e2a\u521b\u5efa\u793a\u4f8b\u5bf9\u8c61\u7684\u00a0<code>Object<\/code>\u00a0\u6784\u9020\u51fd\u6570\u5f15\u7528\u3002\u5f53\u5f53\u524d\u5bf9\u8c61\u662f\u5b57\u7b26\u4e32\u65f6\uff0c\u5b83\u662f\u00a0<code>String<\/code>\uff1b\u5f53\u5f53\u524d\u5bf9\u8c61\u662f\u6570\u5b57\u65f6\uff0c\u5b83\u662f\u00a0<code>Number<\/code>\uff1b\u4ee5\u6b64\u7c7b\u63a8\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/developer.mozilla.org\/en\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Object\/constructor\" rel=\"nofollow\"><code>Object.prototype.constructor<\/code><\/a>\u00a0at MDN<\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-object.prototype.constructor\" rel=\"nofollow\"><strong>19.1.3.1<\/strong>\u00a0Object.prototype.constructor<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u5c06\u5bf9\u8c61\u505a\u4e3a\u53e6\u4e00\u4e2a\u5bf9\u8c61\u7684-key\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%B0%86%E5%AF%B9%E8%B1%A1%E5%81%9A%E4%B8%BA%E5%8F%A6%E4%B8%80%E4%B8%AA%E5%AF%B9%E8%B1%A1%E7%9A%84-key\">\u5c06\u5bf9\u8c61\u505a\u4e3a\u53e6\u4e00\u4e2a\u5bf9\u8c61\u7684 key<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">{<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">]<\/span>: <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span> <span class=\"pl-kos\">}<\/span> <span class=\"pl-c\">\/\/ -&gt; { '[object Object]': {} }<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-31\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-31\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u4e3a\u4f55\u53ef\u4ee5\u6b63\u5e38\u8fd0\u884c\uff1f\u8fd9\u91cc\u6211\u4eec\u4f7f\u7528\u7684\u662f\u00a0<em>\u8ba1\u7b97\u5c5e\u6027<\/em>\u3002\u5f53\u4f60\u5c06\u5bf9\u8c61\u7528\u65b9\u62ec\u53f7\u62ec\u8d77\u6765\u5f53\u4f5c\u5bf9\u8c61\u7684\u5c5e\u6027\u540d\u65f6\uff0c\u5b83\u4f1a\u5c06\u5bf9\u8c61\u5f3a\u5236\u8f6c\u6362\u6210\u4e00\u4e2a\u5b57\u7b26\u4e32\uff0c\u6240\u4ee5\u6211\u4eec\u5f97\u5230\u5c5e\u6027\u952e\u662f\u00a0<code>[object Object]<\/code>\uff0c\u5176\u503c\u4e3a\u00a0<code>{}<\/code>\u3002<\/p>\n<p dir=\"auto\">\u4f53\u9a8c\u4e00\u4e0b\u7b80\u5355\u7684\u201c\u62ec\u53f7\u5730\u72f1\u201d\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">{<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">]<\/span>: <span class=\"pl-kos\">{<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">]<\/span>: <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span> <span class=\"pl-kos\">}<\/span> <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; {}<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ \u7ed3\u6784:<\/span>\r\n<span class=\"pl-c\">\/\/ {<\/span>\r\n<span class=\"pl-c\">\/\/   '[object Object]': {<\/span>\r\n<span class=\"pl-c\">\/\/     '[object Object]': {}<\/span>\r\n<span class=\"pl-c\">\/\/   }<\/span>\r\n<span class=\"pl-c\">\/\/ }<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u5173\u4e8e\u5bf9\u8c61\u5b57\u9762\u91cf\uff0c\u70b9\u51fb\u8fd9\u91cc\u9605\u8bfb\u66f4\u591a\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Operators\/Object_initializer\" rel=\"nofollow\">\u5bf9\u8c61\u521d\u59cb\u5316<\/a>\u00a0at MDN<\/li>\n<\/ul>\n<h2 id=\"user-content-\u8bbf\u95ee\u539f\u578b-__proto__\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E8%AE%BF%E9%97%AE%E5%8E%9F%E5%9E%8B-__proto__\">\u8bbf\u95ee\u539f\u578b\u00a0<code>__proto__<\/code><\/a><\/h2>\n<p dir=\"auto\">\u6211\u4eec\u77e5\u9053\uff0c\u539f\u59cb\u6570\u636e\uff08premitives\uff09\u662f\u6ca1\u6709\u539f\u578b\u7684\u3002\u4f46\u662f\uff0c\u5982\u679c\u6211\u4eec\u5c1d\u8bd5\u83b7\u53d6\u539f\u59cb\u6570\u636e\u7684\u00a0<code>__proto__<\/code>\u00a0\u5c5e\u6027\u7684\u503c\uff0c\u6211\u4eec\u4f1a\u5f97\u5230\u8fd9\u6837\u7684\u4e00\u4e2a\u7ed3\u679c\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">__proto__<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">__proto__<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">__proto__<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; null<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-32\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-32\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8fd9\u662f\u56e0\u4e3a\u539f\u59cb\u6570\u636e\u7684\u6ca1\u6709\u539f\u578b\uff0c\u5b83\u5c06\u4f7f\u7528\u00a0<code>ToObject<\/code>\u00a0\u65b9\u6cd5\u5305\u88c5\u5728\u5305\u88c5\u5668\u5bf9\u8c61\u4e2d\u3002\u8fd9\u4e2a\u6b65\u9aa4\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">__proto__<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; [Number: 0]<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">__proto__<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">__proto__<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; {}<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">__proto__<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">__proto__<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">__proto__<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; null<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4ee5\u4e0b\u662f\u5173\u4e8e\u00a0<code>__proto__<\/code>\u7684\u66f4\u591a\u4fe1\u606f\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-object.prototype.__proto__\" rel=\"nofollow\"><strong>B.2.2.1<\/strong>\u00a0Object.prototype.<strong>proto<\/strong><\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-toobject\" rel=\"nofollow\"><strong>7.1.13<\/strong>\u00a0ToObject(<code>argument<\/code>)<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-object\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#object\"><code>`${{Object}}`<\/code><\/a><\/h2>\n<p dir=\"auto\">\u4e0b\u9762\u7684\u8868\u8fbe\u5f0f\u7ed3\u679c\u5982\u4f55\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-s\">`<span class=\"pl-s1\"><span class=\"pl-kos\">${<\/span><span class=\"pl-kos\">{<\/span> Object <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">}<\/span><\/span>`<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u7b54\u6848\u662f\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/ -&gt; '[object Object]'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-33\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-33\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u6211\u4eec\u901a\u8fc7\u00a0<em>\u7b80\u5199\u5c5e\u6027\u8868\u793a<\/em>\u00a0\u4f7f\u7528\u4e00\u4e2a\u00a0<code>Object<\/code>\u00a0\u5c5e\u6027\u5b9a\u4e49\u4e86\u4e00\u4e2a\u5bf9\u8c61\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">{<\/span>\r\n  Object: <span class=\"pl-v\">Object<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u7136\u540e\u6211\u4eec\u5c06\u8be5\u5bf9\u8c61\u4f20\u9012\u7ed9\u6a21\u677f\u6587\u5b57\uff0c<code>toString<\/code>\u00a0\u65b9\u6cd5\u8c03\u7528\u8be5\u5bf9\u8c61\u3002\u8fd9\u5c31\u662f\u4e3a\u4ec0\u4e48\u6211\u4eec\u5f97\u5230\u5b57\u7b26\u4e32\u00a0<code>'[object Object]'<\/code>\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-template-literals\" rel=\"nofollow\"><strong>12.2.9<\/strong>\u00a0\u6a21\u677f\u5b57\u9762\u91cf<\/a><\/li>\n<li>MDN \u4e0a\u7684\u00a0<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Operators\/Object_initializer\" rel=\"nofollow\">\u5bf9\u8c61\u521d\u59cb\u5316<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u4f7f\u7528\u9ed8\u8ba4\u503c\u89e3\u6784\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E4%BD%BF%E7%94%A8%E9%BB%98%E8%AE%A4%E5%80%BC%E8%A7%A3%E6%9E%84\">\u4f7f\u7528\u9ed8\u8ba4\u503c\u89e3\u6784<\/a><\/h2>\n<p dir=\"auto\">\u8003\u8651\u8fd9\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">let<\/span> <span class=\"pl-s1\">x<\/span><span class=\"pl-kos\">,<\/span>\r\n  <span class=\"pl-kos\">{<\/span> <span class=\"pl-c1\">x<\/span>: <span class=\"pl-s1\">y<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">1<\/span> <span class=\"pl-kos\">}<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span> <span class=\"pl-s1\">x<\/span> <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-s1\">y<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u8fd9\u5728\u9762\u8bd5\u4e2d\u662f\u4e00\u4e2a\u5f88\u597d\u7684\u95ee\u9898\u3002\u95ee\u00a0<code>y<\/code>\u00a0\u7684\u503c\u662f\u4ec0\u4e48\uff1f \u7b54\u6848\u662f\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/ -&gt; 1<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-34\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-34\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">let<\/span> <span class=\"pl-s1\">x<\/span><span class=\"pl-kos\">,<\/span>\r\n  <span class=\"pl-kos\">{<\/span> <span class=\"pl-c1\">x<\/span>: <span class=\"pl-s1\">y<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">1<\/span> <span class=\"pl-kos\">}<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span> <span class=\"pl-s1\">x<\/span> <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-s1\">y<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/  \u2191       \u2191           \u2191    \u2191<\/span>\r\n<span class=\"pl-c\">\/\/  1       3           2    4<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4ee5\u4e0a\u793a\u4f8b\uff1a<\/p>\n<ol dir=\"auto\">\n<li>\u6211\u4eec\u58f0\u660e\u4e86\u00a0<code>x<\/code>\uff0c\u4f46\u6ca1\u6709\u7acb\u523b\u8d4b\u503c\uff0c\u6240\u4ee5\u5b83\u662f\u00a0<code>undefined<\/code>\u3002<\/li>\n<li>\u6211\u4eec\u5c06\u00a0<code>x<\/code>\u00a0\u7684\u503c\u6253\u5305\u5230\u5bf9\u8c61\u5c5e\u6027\u00a0<code>x<\/code>\u00a0\u4e2d\u3002<\/li>\n<li>\u6211\u4eec\u4f7f\u7528\u89e3\u6784\u6765\u63d0\u53d6\u00a0<code>x<\/code>\u00a0\u7684\u503c\uff0c\u5e76\u4e14\u8981\u5c06\u8fd9\u4e2a\u503c\u8d4b\u7ed9\u00a0<code>y<\/code>\u3002\u5982\u679c\u672a\u5b9a\u4e49\u8be5\u503c\uff0c\u90a3\u4e48\u6211\u4eec\u5c06\u4f7f\u7528\u00a0<code>1<\/code>\u00a0\u4f5c\u4e3a\u9ed8\u8ba4\u503c\u3002<\/li>\n<li>\u8fd4\u56de\u00a0<code>y<\/code>\u00a0\u7684\u503c\u3002<\/li>\n<\/ol>\n<ul dir=\"auto\">\n<li>MDN \u4e0a\u7684\u00a0<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Operators\/Object_initializer\" rel=\"nofollow\">\u5bf9\u8c61\u521d\u59cb\u5316<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u70b9\u548c\u6269\u5c55\u8fd0\u7b97\u7b26\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%82%B9%E5%92%8C%E6%89%A9%E5%B1%95%E8%BF%90%E7%AE%97%E7%AC%A6\">\u70b9\u548c\u6269\u5c55\u8fd0\u7b97\u7b26<\/a><\/h2>\n<p dir=\"auto\">\u6570\u7ec4\u7684\u6269\u5c55\u53ef\u4ee5\u7ec4\u6210\u6709\u8da3\u7684\u4f8b\u5b50\u3002\u8003\u8651\u8fd9\u4e2a\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">[<\/span>...<span class=\"pl-kos\">[<\/span>...<span class=\"pl-s\">\"...\"<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">length<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 3<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-35\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-35\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u4e3a\u4ec0\u4e48\u662f 3\uff1f\u5f53\u6211\u4eec\u4f7f\u7528<a href=\"http:\/\/www.ecma-international.org\/ecma-262\/6.0\/#sec-array-initializer\" rel=\"nofollow\">\u6269\u5c55\u8fd0\u7b97\u7b26<\/a>\u65f6\uff0c<code>@@iterator<\/code>\u00a0\u65b9\u6cd5\u4f1a\u88ab\u8c03\u7528\uff0c\u800c\u8fd4\u56de\u7684\u8fed\u4ee3\u5668\u7528\u4e8e\u83b7\u53d6\u8981\u8fed\u4ee3\u7684\u503c\u3002\u5b57\u7b26\u4e32\u7684\u9ed8\u8ba4\u8fed\u4ee3\u5668\u6309\u5b57\u7b26\u5c55\u5f00\u5b57\u7b26\u4e32\u3002\u5c55\u5f00\u4e4b\u540e\uff0c\u6211\u4eec\u628a\u8fd9\u4e9b\u5b57\u7b26\u6253\u5305\u6210\u4e00\u4e2a\u6570\u7ec4\u3002\u7136\u540e\u518d\u5c55\u5f00\u8fd9\u4e2a\u6570\u7ec4\u5e76\u518d\u6253\u5305\u56de\u6570\u7ec4\u3002<\/p>\n<p dir=\"auto\">\u4e00\u4e2a\u00a0<code>'...'<\/code>\u00a0\u5b57\u7b26\u4e32\u5305\u542b\u00a0<code>.<\/code>\u00a0\uff0c\u6240\u4ee5\u7ed3\u679c\u6570\u7ec4\u7684\u957f\u5ea6\u5c06\u00a0<code>3<\/code>\u3002<\/p>\n<p dir=\"auto\">\u73b0\u5728\uff0c\u4e00\u6b65\u4e00\u6b65\u7684\u770b\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">[<\/span>...<span class=\"pl-s\">'...'<\/span><span class=\"pl-kos\">]<\/span>             <span class=\"pl-c\">\/\/ -&gt; [ '.', '.', '.' ]<\/span>\r\n<span class=\"pl-kos\">[<\/span>...<span class=\"pl-kos\">[<\/span>...<span class=\"pl-s\">'...'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span>        <span class=\"pl-c\">\/\/ -&gt; [ '.', '.', '.' ]<\/span>\r\n<span class=\"pl-kos\">[<\/span>...<span class=\"pl-kos\">[<\/span>...<span class=\"pl-s\">'...'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">length<\/span> <span class=\"pl-c\">\/\/ -&gt; 3<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u663e\u7136\uff0c\u6211\u4eec\u53ef\u4ee5\u5c55\u5f00\u548c\u5305\u88c5\u6570\u7ec4\u7684\u5143\u7d20\u4efb\u610f\u591a\u6b21\uff0c\u53ea\u8981\u4f60\u60f3\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">[<\/span>...<span class=\"pl-s\">'...'<\/span><span class=\"pl-kos\">]<\/span>                 <span class=\"pl-c\">\/\/ -&gt; [ '.', '.', '.' ]<\/span>\r\n<span class=\"pl-kos\">[<\/span>...<span class=\"pl-kos\">[<\/span>...<span class=\"pl-s\">'...'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span>            <span class=\"pl-c\">\/\/ -&gt; [ '.', '.', '.' ]<\/span>\r\n<span class=\"pl-kos\">[<\/span>...<span class=\"pl-kos\">[<\/span>...<span class=\"pl-kos\">[<\/span>...<span class=\"pl-s\">'...'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span>       <span class=\"pl-c\">\/\/ -&gt; [ '.', '.', '.' ]<\/span>\r\n<span class=\"pl-kos\">[<\/span>...<span class=\"pl-kos\">[<\/span>...<span class=\"pl-kos\">[<\/span>...<span class=\"pl-kos\">[<\/span>...<span class=\"pl-s\">'...'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span>  <span class=\"pl-c\">\/\/ -&gt; [ '.', '.', '.' ]<\/span>\r\n<span class=\"pl-c\">\/\/ \u4ee5\u6b64\u7c7b\u63a8 \u2026<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h2 id=\"user-content-\u6807\u7b7e\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%A0%87%E7%AD%BE\">\u6807\u7b7e<\/a><\/h2>\n<p dir=\"auto\">\u5f88\u591a\u7a0b\u5e8f\u5458\u4e0d\u77e5\u9053 JavaScript \u4e2d\u4e5f\u6709\u6807\u7b7e\uff0c\u5e76\u4e14\u5f88\u6709\u8da3\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre>foo: <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"first\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-k\">break<\/span> foo<span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"second\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ &gt; first<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt; undefined<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-36\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-36\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u5e26\u6807\u7b7e\u7684\u8bed\u53e5\u4e0e\u00a0<code>break<\/code>\u00a0\u6216\u00a0<code>continue<\/code>\u00a0\u8bed\u53e5\u4e00\u8d77\u4f7f\u7528\u3002\u60a8\u53ef\u4ee5\u4f7f\u7528\u6807\u7b7e\u6765\u6807\u8bc6\u5faa\u73af\uff0c\u7136\u540e\u4f7f\u7528\u00a0<code>break<\/code>\u00a0\u6216\u00a0<code>continue<\/code>\u00a0\u8bed\u53e5\u6765\u6307\u793a\u7a0b\u5e8f\u662f\u5426\u5e94\u8be5\u4e2d\u65ad\u5faa\u73af\u6216\u7ee7\u7eed\u6267\u884c\u5b83\u3002<\/p>\n<p dir=\"auto\">\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u8bc6\u522b\u4e00\u4e2a\u6807\u7b7e\u00a0<code>foo<\/code>\u3002\u7136\u540e\u00a0<code>console.log\uff08'first'\uff09;<\/code>\u00a0\u6267\u884c\uff0c\u7136\u540e\u4e2d\u65ad\u6267\u884c\u3002<\/p>\n<p dir=\"auto\">\u8be6\u7ec6\u4e86\u89e3 JavaScript \u4e2d\u7684\u6807\u7b7e\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/tc39.github.io\/ecma262\/#sec-labelled-statements\" rel=\"nofollow\"><strong>13.13<\/strong>\u00a0\u6807\u7b7e\u8bed\u53e5<\/a><\/li>\n<li><a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Statements\/label\" rel=\"nofollow\">\u6807\u7b7e\u8bed\u53e5<\/a>\u00a0at MDN<\/li>\n<\/ul>\n<h2 id=\"user-content-\u5d4c\u5957\u6807\u7b7e\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%B5%8C%E5%A5%97%E6%A0%87%E7%AD%BE\">\u5d4c\u5957\u6807\u7b7e<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre>a: b: c: d: e: f: g: <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">5<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 5<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-37\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-37\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u548c\u4e0a\u9762\u7684\u4f8b\u5b50\u7c7b\u4f3c\uff0c\u8bf7\u9075\u5faa\u4ee5\u4e0b\u94fe\u63a5\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-comma-operator\" rel=\"nofollow\"><strong>12.16<\/strong>\u00a0\u9017\u53f7\u8fd0\u7b97\u7b26(<code>,<\/code>)<\/a><\/li>\n<li><a href=\"https:\/\/tc39.github.io\/ecma262\/#sec-labelled-statements\" rel=\"nofollow\"><strong>13.13<\/strong>\u00a0\u6807\u7b7e\u8bed\u53e5<\/a><\/li>\n<li><a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Statements\/label\" rel=\"nofollow\">\u6807\u7b7e\u8bed\u53e5<\/a>\u00a0at MDN<\/li>\n<\/ul>\n<h2 id=\"user-content-\u9634\u9669\u7684-trycatch\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E9%98%B4%E9%99%A9%E7%9A%84-trycatch\">\u9634\u9669\u7684\u00a0<code>try..catch<\/code><\/a><\/h2>\n<p dir=\"auto\">\u8fd9\u4e2a\u8868\u8fbe\u5f0f\u5c06\u8fd4\u56de\u4ec0\u4e48\uff1f<code>2<\/code>\u00a0\u8fd8\u662f\u00a0<code>3<\/code>\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-k\">try<\/span> <span class=\"pl-kos\">{<\/span>\r\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-kos\">}<\/span> <span class=\"pl-k\">finally<\/span> <span class=\"pl-kos\">{<\/span>\r\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u7b54\u6848\u662f\u00a0<code>3<\/code>\u3002\u60ca\u8bb6\u5417\uff1f<\/p>\n<h3 id=\"user-content--\u8bf4\u660e-38\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-38\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-try-statement\" rel=\"nofollow\"><strong>13.15<\/strong>\u00a0<code>try<\/code>\u00a0\u8bed\u53e5<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u8fd9\u662f\u591a\u91cd\u7ee7\u627f\u5417\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E8%BF%99%E6%98%AF%E5%A4%9A%E9%87%8D%E7%BB%A7%E6%89%BF%E5%90%97\">\u8fd9\u662f\u591a\u91cd\u7ee7\u627f\u5417\uff1f<\/a><\/h2>\n<p dir=\"auto\">\u770b\u4e0b\u9762\u7684\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">new<\/span> <span class=\"pl-k\">class<\/span> <span class=\"pl-v\">F<\/span> <span class=\"pl-k\">extends<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-v\">String<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-v\">Array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; F []<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u8fd9\u662f\u591a\u91cd\u7ee7\u627f\u5417\uff1f\u4e0d\u3002<\/p>\n<h3 id=\"user-content--\u8bf4\u660e-39\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-39\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u6709\u8da3\u7684\u90e8\u5206\u662f\u00a0<code>extends<\/code>\u00a0\u5b50\u53e5\u7684\u503c\uff08<code>\uff08String\uff0cArray\uff09<\/code>\uff09\u3002\u5206\u7ec4\u8fd0\u7b97\u7b26\u603b\u662f\u8fd4\u56de\u5176\u6700\u540e\u4e00\u4e2a\u53c2\u6570\uff0c\u6240\u4ee5\u00a0<code>\uff08String\uff0cArray\uff09<\/code>\u00a0\u5b9e\u9645\u4e0a\u53ea\u662f\u00a0<code>Array<\/code>\u3002 \u8fd9\u610f\u5473\u7740\u6211\u4eec\u521a\u521a\u521b\u5efa\u4e86\u4e00\u4e2a\u6269\u5c55\u00a0<code>Array<\/code>\u00a0\u7684\u7c7b\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-class-definitions\" rel=\"nofollow\"><strong>14.5<\/strong>\u00a0\u7c7b\u5b9a\u4e49<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-comma-operator\" rel=\"nofollow\"><strong>12.16<\/strong>\u00a0\u9017\u53f7\u8fd0\u7b97\u7b26 (<code>,<\/code>)<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-yield-\u8fd4\u56de\u81ea\u8eab\u7684\u751f\u6210\u5668\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#yield-%E8%BF%94%E5%9B%9E%E8%87%AA%E8%BA%AB%E7%9A%84%E7%94%9F%E6%88%90%E5%99%A8\">yield \u8fd4\u56de\u81ea\u8eab\u7684\u751f\u6210\u5668<\/a><\/h2>\n<p dir=\"auto\">\u8003\u8651\u8fd9\u4e2a yield \u8fd4\u56de\u81ea\u8eab\u7684\u751f\u6210\u5668\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">function<\/span><span class=\"pl-c1\">*<\/span> <span class=\"pl-s1\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-k\">yield<\/span> <span class=\"pl-s1\">f<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">next<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt; { value: [GeneratorFunction: f], done: false }<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u5982\u60a8\u6240\u89c1\uff0c\u8fd4\u56de\u7684\u503c\u662f\u4e00\u4e2a\u503c\u7b49\u4e8e\u00a0<code>f<\/code>\u00a0\u7684\u5bf9\u8c61\u3002\u90a3\u6837\u7684\u8bdd\uff0c\u6211\u4eec\u53ef\u4ee5\u505a\u8fd9\u6837\u7684\u4e8b\u60c5\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">function<\/span><span class=\"pl-c1\">*<\/span> <span class=\"pl-s1\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-k\">yield<\/span> <span class=\"pl-s1\">f<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">next<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">value<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">next<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span>\r\n    <span class=\"pl-c\">\/\/ -&gt; { value: [GeneratorFunction: f], done: false }<\/span>\r\n\r\n    <span class=\"pl-c\">\/\/ \u518d\u4e00\u6b21<\/span>\r\n    <span class=\"pl-k\">function<\/span><span class=\"pl-c1\">*<\/span> <span class=\"pl-s1\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n      <span class=\"pl-k\">yield<\/span> <span class=\"pl-s1\">f<\/span><span class=\"pl-kos\">;<\/span>\r\n    <span class=\"pl-kos\">}<\/span>\r\n  <span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">next<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">value<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">next<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">value<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">next<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span>\r\n    <span class=\"pl-c\">\/\/ -&gt; { value: [GeneratorFunction: f], done: false }<\/span>\r\n\r\n    <span class=\"pl-c\">\/\/ \u518d\u4e00\u6b21<\/span>\r\n    <span class=\"pl-k\">function<\/span><span class=\"pl-c1\">*<\/span> <span class=\"pl-s1\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n      <span class=\"pl-k\">yield<\/span> <span class=\"pl-s1\">f<\/span><span class=\"pl-kos\">;<\/span>\r\n    <span class=\"pl-kos\">}<\/span>\r\n  <span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">next<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">value<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">next<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">value<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">next<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">value<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\r\n  <span class=\"pl-kos\">.<\/span><span class=\"pl-en\">next<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt; { value: [GeneratorFunction: f], done: false }<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ \u4ee5\u6b64\u7c7b\u63a8<\/span>\r\n<span class=\"pl-c\">\/\/ \u2026<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-40\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-40\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8981\u7406\u89e3\u4e3a\u4ec0\u4e48\u8fd9\u6837\u5de5\u4f5c\uff0c\u8bf7\u9605\u8bfb\u89c4\u8303\u7684\u8fd9\u4e9b\u90e8\u5206\uff1a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-control-abstraction-objects\" rel=\"nofollow\"><strong>25<\/strong>\u00a0\u63a7\u5236\u6d41\u62bd\u8c61\u5bf9\u8c61<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-generator-objects\" rel=\"nofollow\"><strong>25.3<\/strong>\u00a0\u751f\u6210\u5668\u5bf9\u8c61<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u7c7b\u7684\u7c7b\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%B1%BB%E7%9A%84%E7%B1%BB\">\u7c7b\u7684\u7c7b<\/a><\/h2>\n<p dir=\"auto\">\u8003\u8651\u8fd9\u4e2a\u6df7\u6dc6\u8bed\u6cd5\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">typeof<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-k\">class<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-en\">class<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'object'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4f3c\u4e4e\u6211\u4eec\u5728\u7c7b\u5185\u90e8\u58f0\u660e\u4e86\u4e00\u4e2a\u7c7b\u3002\u5e94\u8be5\u662f\u4e2a\u9519\u8bef\uff0c\u7136\u800c\uff0c\u6211\u4eec\u5f97\u5230\u4e00\u4e2a\u00a0<code>'object'<\/code>\u00a0\u5b57\u7b26\u4e32\u3002<\/p>\n<h3 id=\"user-content--\u8bf4\u660e-41\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-41\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">ECMAScript 5 \u65f6\u4ee3\u4ee5\u6765\uff0c\u5141\u8bb8\u00a0<em>\u5173\u952e\u5b57<\/em>\u00a0\u4f5c\u4e3a\u00a0<em>\u5c5e\u6027\u540d\u79f0<\/em>\u3002\u8bf7\u770b\u4e0b\u9762\u8fd9\u4e2a\u7b80\u5355\u7684\u5bf9\u8c61\u793a\u4f8b\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">foo<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-en\">class<\/span>: <span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u8fd8\u6709 ES6 \u6807\u51c6\u4e2d\u7684\u7b80\u5199\u65b9\u6cd5\u5b9a\u4e49\u3002\u6b64\u5916\uff0c\u7c7b\u4e5f\u53ef\u4ee5\u662f\u533f\u540d\u7684\u3002\u56e0\u6b64\uff0c\u5982\u679c\u6211\u4eec\u5220\u53bb\u00a0<code>: function<\/code>\u00a0\u90e8\u5206\uff0c\u5c06\u4f1a\u5f97\u5230\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">class<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-en\">class<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-kos\">}<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u9ed8\u8ba4\u7c7b\u7684\u7ed3\u679c\u603b\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u5bf9\u8c61\u3002\u5176\u7c7b\u578b\u5e94\u8fd4\u56de\u00a0<code>'object'<\/code>\u00a0\u3002<\/p>\n<p dir=\"auto\">\u5728\u8fd9\u91cc\u9605\u8bfb\u66f4\u591a<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-method-definitions\" rel=\"nofollow\"><strong>14.3<\/strong>\u00a0\u65b9\u6cd5\u5b9a\u4e49<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-class-definitions\" rel=\"nofollow\"><strong>14.5<\/strong>\u00a0\u7c7b\u5b9a\u4e49<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u4e0d\u53ef\u8f6c\u6362\u7c7b\u578b\u7684\u5bf9\u8c61\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E4%B8%8D%E5%8F%AF%E8%BD%AC%E6%8D%A2%E7%B1%BB%E5%9E%8B%E7%9A%84%E5%AF%B9%E8%B1%A1\">\u4e0d\u53ef\u8f6c\u6362\u7c7b\u578b\u7684\u5bf9\u8c61<\/a><\/h2>\n<p dir=\"auto\">\u6709\u4e00\u79cd\u65b9\u6cd5\u53ef\u4ee5\u6446\u8131\u7c7b\u578b\u7684\u8f6c\u6362\uff0c\u90a3\u5c31\u662f\u4f7f\u7528\u5185\u7f6e\u7b26\u53f7\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">function<\/span> <span class=\"pl-en\">nonCoercible<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">val<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">val<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n    <span class=\"pl-k\">throw<\/span> <span class=\"pl-v\">TypeError<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"nonCoercible should not be called with null or undefined\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-kos\">}<\/span>\r\n\r\n  <span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">res<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-v\">Object<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">val<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n  <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-v\">Symbol<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">toPrimitive<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-kos\">{<\/span>\r\n    <span class=\"pl-k\">throw<\/span> <span class=\"pl-v\">TypeError<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"Trying to coerce non-coercible object\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n  <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u73b0\u5728\u6211\u4eec\u53ef\u4ee5\u8fd9\u6837\u4f7f\u7528\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/ \u5bf9\u8c61<\/span>\r\n<span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">foo<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-en\">nonCoercible<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">{<\/span> <span class=\"pl-c1\">foo<\/span>: <span class=\"pl-s\">\"foo\"<\/span> <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n<span class=\"pl-s1\">foo<\/span> <span class=\"pl-c1\">*<\/span> <span class=\"pl-c1\">10<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; TypeError: Trying to coerce non-coercible object<\/span>\r\n<span class=\"pl-s1\">foo<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-s\">\"evil\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; TypeError: Trying to coerce non-coercible object<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ \u5b57\u7b26\u4e32<\/span>\r\n<span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">bar<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-en\">nonCoercible<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"bar\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n<span class=\"pl-s1\">bar<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-s\">\"1\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; TypeError: Trying to coerce non-coercible object<\/span>\r\n<span class=\"pl-s1\">bar<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toString<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; bar1<\/span>\r\n<span class=\"pl-s1\">bar<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-s\">\"bar\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-s1\">bar<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toString<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-s\">\"bar\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-s1\">bar<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">\"bar\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; TypeError: Trying to coerce non-coercible object<\/span>\r\n\r\n<span class=\"pl-c\">\/\/ \u6570\u5b57<\/span>\r\n<span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">baz<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-en\">nonCoercible<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n<span class=\"pl-s1\">baz<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; TypeError: Trying to coerce non-coercible object<\/span>\r\n<span class=\"pl-s1\">baz<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-s1\">baz<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">valueOf<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-42\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-42\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/gist.github.com\/chicoxyzzy\/5dd24608e886adf5444499896dff1197\">Sergey Rubanov \u7684 gist<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-well-known-symbols\" rel=\"nofollow\"><strong>6.1.5.1<\/strong>\u00a0\u5185\u7f6e\u7b26\u53f7<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u68d8\u624b\u7684\u7bad\u5934\u51fd\u6570\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%A3%98%E6%89%8B%E7%9A%84%E7%AE%AD%E5%A4%B4%E5%87%BD%E6%95%B0\">\u68d8\u624b\u7684\u7bad\u5934\u51fd\u6570<\/a><\/h2>\n<p dir=\"auto\">\u8003\u8651\u4e0b\u9762\u7684\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">let<\/span> <span class=\"pl-en\">f<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-c1\">10<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 10<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u8fd9\u770b\u8d77\u6765\u6ca1\u95ee\u9898\uff0c\u4f46\u662f\u5982\u679c\u8fd9\u6837\u5462\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">let<\/span> <span class=\"pl-en\">f<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; undefined<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-43\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-43\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u4f60\u53ef\u80fd\u89c9\u5f97\u5e94\u8be5\u8fd4\u56de\u00a0<code>{}<\/code>\u00a0\u800c\u4e0d\u662f\u00a0<code>undefined<\/code>\u3002\u8fd9\u662f\u56e0\u4e3a\u82b1\u62ec\u53f7\u662f\u7bad\u5934\u51fd\u6570\u8bed\u6cd5\u7684\u4e00\u90e8\u5206\uff0c\u6240\u4ee5\u00a0<code>f<\/code>\u00a0\u4f1a\u8fd4\u56de\u00a0<code>undefined<\/code>\u3002\u4e0d\u8fc7\u8981\u4ece\u7bad\u5934\u51fd\u6570\u660e\u786e\u8fd4\u56de\u00a0<code>{}<\/code>\u00a0\u5bf9\u8c61\u4e5f\u662f\u6709\u53ef\u80fd\u7684\uff0c\u8fd9\u65f6\u4f60\u9700\u8981\u7528\u62ec\u53f7\u628a\u8fd4\u56de\u503c\u62ec\u8d77\u6765\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">let<\/span> <span class=\"pl-en\">f<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; {}<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h2 id=\"user-content-\u7bad\u5934\u51fd\u6570\u4e0d\u80fd\u4f5c\u4e3a\u6784\u9020\u51fd\u6570\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%AE%AD%E5%A4%B4%E5%87%BD%E6%95%B0%E4%B8%8D%E8%83%BD%E4%BD%9C%E4%B8%BA%E6%9E%84%E9%80%A0%E5%87%BD%E6%95%B0\">\u7bad\u5934\u51fd\u6570\u4e0d\u80fd\u4f5c\u4e3a\u6784\u9020\u51fd\u6570<\/a><\/h2>\n<p dir=\"auto\">\u8003\u8651\u4e0b\u9762\u7684\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">let<\/span> <span class=\"pl-en\">f<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-smi\">this<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">a<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-k\">new<\/span> <span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; { 'a': 1 }<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u73b0\u5728\uff0c\u8bd5\u7740\u7528\u7bad\u5934\u51fd\u6570\u505a\u540c\u6837\u7684\u4e8b\u60c5\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">let<\/span> <span class=\"pl-en\">f<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-smi\">this<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">a<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-k\">new<\/span> <span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; TypeError: f is not a constructor<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-44\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-44\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u7bad\u5934\u51fd\u6570\u4e0d\u80fd\u4f5c\u4e3a\u6784\u9020\u51fd\u6570\u8c03\u7528\uff0c\u5e76\u4e14\u4f1a\u5728\u00a0<code>new<\/code>\u00a0\u7684\u65f6\u5019\u629b\u51fa\u9519\u8bef\u3002\u56e0\u4e3a\u5b83\u5177\u6709\u8bcd\u57df\u00a0<code>this<\/code>\uff0c\u800c\u4e14\u5b83\u4e5f\u6ca1\u6709\u00a0<code>prototype<\/code>\u00a0\u5c5e\u6027\uff0c\u6240\u4ee5\u8fd9\u6837\u505a\u6ca1\u4ec0\u4e48\u610f\u4e49\u3002<\/p>\n<h2 id=\"user-content-arguments-\u548c\u7bad\u5934\u51fd\u6570\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#arguments-%E5%92%8C%E7%AE%AD%E5%A4%B4%E5%87%BD%E6%95%B0\"><code>arguments<\/code>\u00a0\u548c\u7bad\u5934\u51fd\u6570<\/a><\/h2>\n<p dir=\"auto\">\u8003\u8651\u4e0b\u9762\u7684\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">let<\/span> <span class=\"pl-en\">f<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-k\">return<\/span> <span class=\"pl-smi\">arguments<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"a\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; { '0': 'a' }<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u73b0\u5728\uff0c\u8bd5\u7740\u7528\u7bad\u5934\u51fd\u6570\u505a\u540c\u6837\u7684\u4e8b\u60c5\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">let<\/span> <span class=\"pl-en\">f<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-smi\">arguments<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"a\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; Uncaught ReferenceError: arguments is not defined<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-45\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-45\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u7bad\u5934\u51fd\u6570\u662f\u5e38\u89c4\u51fd\u6570\u7684\u8f7b\u91cf\u7ea7\u7248\u672c\uff0c\u6ce8\u91cd\u4e8e\u77ed\u5c0f\u548c\u8bcd\u57df\u00a0<code>this<\/code>\u3002\u540c\u65f6\u7bad\u5934\u51fd\u6570\u4e0d\u63d0\u4f9b\u00a0<code>arguments<\/code>\u00a0\u5bf9\u8c61\u7684\u7ed1\u5b9a\u3002\u4f60\u53ef\u4ee5\u4f7f\u7528\u00a0<code>\u5269\u4f59\u53c2\u6570\uff08rest parameters\uff09<\/code>\u00a0\u6765\u5f97\u5230\u540c\u6837\u7684\u7ed3\u679c\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">let<\/span> <span class=\"pl-en\">f<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">(<\/span>...<span class=\"pl-s1\">args<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-s1\">args<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-en\">f<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"a\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<ul dir=\"auto\">\n<li>MDN \u4e0a\u7684\u00a0<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Functions\/Arrow_functions\" rel=\"nofollow\">\u7bad\u5934\u51fd\u6570<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u68d8\u624b\u7684\u8fd4\u56de\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%A3%98%E6%89%8B%E7%9A%84%E8%BF%94%E5%9B%9E\">\u68d8\u624b\u7684\u8fd4\u56de<\/a><\/h2>\n<p dir=\"auto\"><code>return<\/code>\u00a0\u8bed\u53e5\u662f\u5f88\u68d8\u624b\u7684. \u770b\u4e0b\u9762\u7684\u4ee3\u7801:<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-k\">return<\/span>\r\n  <span class=\"pl-kos\">{<\/span>\r\n    b: <span class=\"pl-c1\">10<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; undefined<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-46\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-46\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\"><code>return<\/code>\u00a0\u548c\u8fd4\u56de\u7684\u8868\u8fbe\u5f0f\u5fc5\u987b\u5728\u540c\u4e00\u884c:<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-k\">return<\/span> <span class=\"pl-kos\">{<\/span>\r\n    <span class=\"pl-c1\">b<\/span>: <span class=\"pl-c1\">10<\/span>\r\n  <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; { b: 10 }<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u8fd9\u662f\u56e0\u4e3a\u4e00\u4e2a\u53eb\u81ea\u52a8\u5206\u53f7\u63d2\u5165\u7684\u6982\u5ff5\uff0c\u5b83\u4f1a\u5728\u5927\u90e8\u5206\u6362\u884c\u5904\u63d2\u5165\u5206\u53f7\u3002\u7b2c\u4e00\u4e2a\u4f8b\u5b50\u91cc\uff0c<code>return<\/code>\u00a0\u8bed\u53e5\u548c\u5bf9\u8c61\u5b57\u9762\u91cf\u4e2d\u95f4\u88ab\u63d2\u5165\u4e86\u4e00\u4e2a\u5206\u53f7\u3002\u6240\u4ee5\u51fd\u6570\u8fd4\u56de\u00a0<code>undefined<\/code>\uff0c\u5176\u540e\u7684\u5bf9\u8c61\u5b57\u9762\u91cf\u6c38\u8fdc\u4e0d\u4f1a\u88ab\u6c42\u503c\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-rules-of-automatic-semicolon-insertion\" rel=\"nofollow\"><strong>11.9.1<\/strong>\u00a0\u81ea\u52a8\u5206\u53f7\u63d2\u5165\u7684\u89c4\u5219<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-return-statement\" rel=\"nofollow\"><strong>13.10<\/strong>\u00a0<code>return<\/code>\u00a0\u8bed\u53e5<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u5bf9\u8c61\u7684\u94fe\u5f0f\u8d4b\u503c\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%AF%B9%E8%B1%A1%E7%9A%84%E9%93%BE%E5%BC%8F%E8%B5%8B%E5%80%BC\">\u5bf9\u8c61\u7684\u94fe\u5f0f\u8d4b\u503c<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">foo<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span> <span class=\"pl-c1\">n<\/span>: <span class=\"pl-c1\">1<\/span> <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">bar<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">foo<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n<span class=\"pl-s1\">foo<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">x<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">foo<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span> <span class=\"pl-c1\">n<\/span>: <span class=\"pl-c1\">2<\/span> <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n<span class=\"pl-s1\">foo<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">x<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; undefined<\/span>\r\n<span class=\"pl-s1\">foo<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; {n: 2}<\/span>\r\n<span class=\"pl-s1\">bar<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; {n: 1, x: {n: 2}}<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4ece\u53f3\u5230\u5de6\uff0c<code>{n: 2}<\/code>\u00a0\u88ab\u8d4b\u503c\u7ed9\u00a0<code>foo<\/code>\uff0c\u800c\u6b64\u8d4b\u503c\u7684\u7ed3\u679c\u00a0<code>{n: 2}<\/code>\u00a0\u88ab\u8d4b\u503c\u7ed9\u00a0<code>foo.x<\/code>\uff0c\u56e0\u6b64\u00a0<code>bar<\/code>\u00a0\u662f\u00a0<code>{n: 1, x: {n: 2}}<\/code>\uff0c\u6bd5\u7adf\u00a0<code>bar<\/code>\u00a0\u662f\u00a0<code>foo<\/code>\u00a0\u7684\u4e00\u4e2a\u5f15\u7528\u3002\u4f46\u4e3a\u4ec0\u4e48\u00a0<code>foo.x<\/code>\u00a0\u662f\u00a0<code>undefined<\/code>\u00a0\u800c\u00a0<code>bar.x<\/code>\u00a0\u4e0d\u662f\u5462\uff1f<\/p>\n<h3 id=\"user-content--\u8bf4\u660e-47\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-47\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\"><code>foo<\/code>\u00a0\u548c\u00a0<code>bar<\/code>\u00a0\u5f15\u7528\u540c\u4e00\u4e2a\u5bf9\u8c61\u00a0<code>{n: 1}<\/code>\uff0c\u800c\u5de6\u503c\u5728\u8d4b\u503c\u524d\u89e3\u6790\u3002<code>foo = {n: 2}<\/code>\u00a0\u662f\u521b\u5efa\u4e00\u4e2a\u65b0\u5bf9\u8c61\uff0c\u6240\u4ee5\u00a0<code>foo<\/code>\u00a0\u88ab\u66f4\u65b0\u4e3a\u5f15\u7528\u90a3\u4e2a\u65b0\u7684\u5bf9\u8c61\u3002\u56e0\u4e3a\u00a0<code>foo.x = ...<\/code>\u00a0\u4e2d\u7684\u00a0<code>foo<\/code>\u00a0\u4f5c\u4e3a\u5de6\u503c\u5728\u8d4b\u503c\u524d\u5c31\u88ab\u89e3\u6790\u5e76\u4f9d\u7136\u5f15\u7528\u65e7\u7684\u00a0<code>foo = {n: 1}<\/code>\u00a0\u5bf9\u8c61\u5e76\u4e3a\u5176\u6dfb\u52a0\u4e86\u00a0<code>x<\/code>\u00a0\u503c\u3002\u5728\u94fe\u5f0f\u8d4b\u503c\u4e4b\u540e\uff0c<code>bar<\/code>\u00a0\u4f9d\u7136\u5f15\u7528\u65e7\u7684\u00a0<code>foo<\/code>\u00a0\u5bf9\u8c61\uff0c\u4f46\u00a0<code>foo<\/code>\u00a0\u66f4\u65b0\u4e3a\u6ca1\u6709\u00a0<code>x<\/code>\u00a0\u5c5e\u6027\u7684\u00a0<code>{n: 2}<\/code>\u00a0\u5bf9\u8c61\u3002<\/p>\n<p dir=\"auto\">\u5b83\u7b49\u4ef7\u4e8e\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">foo<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span> <span class=\"pl-c1\">n<\/span>: <span class=\"pl-c1\">1<\/span> <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">bar<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">foo<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n<span class=\"pl-s1\">foo<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span> <span class=\"pl-c1\">n<\/span>: <span class=\"pl-c1\">2<\/span> <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; {n: 2}<\/span>\r\n<span class=\"pl-s1\">bar<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">x<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">foo<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; {n: 1, x: {n: 2}}<\/span>\r\n<span class=\"pl-c\">\/\/ bar.x \u6307\u5411\u65b0\u7684 foo \u5bf9\u8c61\u7684\u5730\u5740<\/span>\r\n<span class=\"pl-c\">\/\/ \u8fd9\u4e0d\u7b49\u4ef7\u4e8e\uff1abar.x = {n: 2}<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h2 id=\"user-content-\u4f7f\u7528\u6570\u7ec4\u8bbf\u95ee\u5bf9\u8c61\u5c5e\u6027\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E4%BD%BF%E7%94%A8%E6%95%B0%E7%BB%84%E8%AE%BF%E9%97%AE%E5%AF%B9%E8%B1%A1%E5%B1%9E%E6%80%A7\">\u4f7f\u7528\u6570\u7ec4\u8bbf\u95ee\u5bf9\u8c61\u5c5e\u6027<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">obj<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span> <span class=\"pl-c1\">property<\/span>: <span class=\"pl-c1\">1<\/span> <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-s\">\"property\"<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n<span class=\"pl-s1\">obj<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 1<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u90a3\u5173\u4e8e\u4f2a\u591a\u7ef4\u6570\u7ec4\u521b\u5efa\u5bf9\u8c61\u5462\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">map<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">x<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">y<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">z<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n<span class=\"pl-s1\">map<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">x<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">y<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">z<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-s1\">map<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">x<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">10<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">y<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">z<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span>\r\n\r\n<span class=\"pl-s1\">map<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s\">\"1,2,3\"<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-s1\">map<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s\">\"11,2,3\"<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-48\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-48\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\"><code>[]<\/code>\u00a0\u64cd\u4f5c\u7b26\u4f1a\u4f7f\u7528\u00a0<code>toString<\/code>\u00a0\u5c06\u4f20\u9012\u7684\u8868\u8fbe\u5f0f\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\u3002\u5c06\u5355\u5143\u7d20\u6570\u7ec4\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\uff0c\u76f8\u5f53\u4e8e\u5c06\u8fd9\u4e2a\u5143\u7d20\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">[<\/span><span class=\"pl-s\">\"property\"<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toString<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'property'`<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h2 id=\"user-content-numbertofixed-\u663e\u793a\u4e0d\u540c\u7684\u6570\u5b57\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#numbertofixed-%E6%98%BE%E7%A4%BA%E4%B8%8D%E5%90%8C%E7%9A%84%E6%95%B0%E5%AD%97\"><code>Number.toFixed()<\/code>\u00a0\u663e\u793a\u4e0d\u540c\u7684\u6570\u5b57<\/a><\/h2>\n<p dir=\"auto\"><code>Number.toFixed()<\/code>\u00a0\u5728\u4e0d\u540c\u7684\u6d4f\u89c8\u5668\u4e2d\u4f1a\u8868\u73b0\u5f97\u6709\u70b9\u5947\u602a\u3002\u770b\u770b\u8fd9\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">0.7875<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toFixed<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ Firefox: -&gt; 0.787<\/span>\r\n<span class=\"pl-c\">\/\/ Chrome: -&gt; 0.787<\/span>\r\n<span class=\"pl-c\">\/\/ IE11: -&gt; 0.788<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">0.7876<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toFixed<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ Firefox: -&gt; 0.788<\/span>\r\n<span class=\"pl-c\">\/\/ Chrome: -&gt; 0.788<\/span>\r\n<span class=\"pl-c\">\/\/ IE11: -&gt; 0.788<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-49\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-49\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u5c3d\u7ba1\u4f60\u7684\u7b2c\u4e00\u76f4\u89c9\u53ef\u80fd\u662f IE11 \u662f\u6b63\u786e\u7684\u800c Firefox\/Chrome \u9519\u4e86\uff0c\u4e8b\u5b9e\u662f Firefox\/Chrome \u66f4\u76f4\u63a5\u5730\u9075\u5faa\u6570\u5b57\u8fd0\u7b97\u7684\u6807\u51c6\uff08IEEE-754 Floating Point\uff09\uff0c\u800c IE11 \u7ecf\u5e38\u8fdd\u53cd\u5b83\u4eec\uff08\u53ef\u80fd\uff09\u53bb\u52aa\u529b\u5f97\u51fa\u66f4\u6e05\u6670\u7684\u7ed3\u679c\u3002<\/p>\n<p dir=\"auto\">\u4f60\u53ef\u4ee5\u901a\u8fc7\u4e00\u4e9b\u5feb\u901f\u7684\u6d4b\u8bd5\u6765\u4e86\u89e3\u4e3a\u4ec0\u4e48\u5b83\u4eec\u53d1\u751f\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/ \u786e\u8ba4 5 \u5411\u4e0b\u53d6\u6574\u7684\u5947\u602a\u7ed3\u679c<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">0.7875<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toFixed<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">3<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 0.787<\/span>\r\n<span class=\"pl-c\">\/\/ \u5f53\u4f60\u5c55\u5f00\u5230 64 \u4f4d\uff08\u53cc\u7cbe\u5ea6\uff09\u6d6e\u70b9\u6570\u51c6\u786e\u5ea6\u9650\u5236\u65f6\u770b\u8d77\u6765\u5c31\u662f\u4e00\u4e2a 5<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">0.7875<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toFixed<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">14<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 0.78750000000000<\/span>\r\n<span class=\"pl-c\">\/\/ \u4f46\u5982\u679c\u4f60\u8d85\u8d8a\u8fd9\u4e2a\u9650\u5236\u5462\uff1f<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">0.7875<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toFixed<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">20<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 0.78749999999999997780<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u6d6e\u70b9\u6570\u5728\u8ba1\u7b97\u673a\u5185\u90e8\u4e0d\u662f\u4ee5\u4e00\u7cfb\u5217\u5341\u8fdb\u5236\u6570\u5b57\u7684\u5f62\u5f0f\u5b58\u50a8\u7684\uff0c\u800c\u662f\u901a\u8fc7\u4e00\u4e2a\u53ef\u4ee5\u4ea7\u751f\u4e00\u70b9\u70b9\u901a\u5e38\u4f1a\u88ab toString \u6216\u8005\u5176\u4ed6\u8c03\u7528\u53d6\u6574\u7684\u4e0d\u51c6\u786e\u6027\u7684\u66f4\u590d\u6742\u7684\u65b9\u6cd5\uff0c\u4f46\u5b83\u5b9e\u9645\u4e0a\u5728\u5185\u90e8\u4f1a\u88ab\u8868\u793a\u3002<\/p>\n<p dir=\"auto\">\u5728\u8fd9\u91cc\uff0c\u90a3\u4e2a\u7ed3\u5c3e\u7684 &#8220;5&#8221; \u5b9e\u9645\u4e0a\u662f\u4e00\u4e2a\u6781\u5176\u5c0f\u7684\u7565\u5c0f\u4e8e 5 \u7684\u5206\u6570\u3002\u5c06\u5176\u4ee5\u4efb\u4f55\u5e38\u7406\u7684\u957f\u5ea6\u53d6\u6574\u5b83\u90fd\u4f1a\u88ab\u770b\u4f5c\u4e00\u4e2a 5\uff0c\u4f46\u5b83\u5728\u5185\u90e8\u901a\u5e38\u4e0d\u662f 5\u3002<\/p>\n<p dir=\"auto\">\u7136\u800c IE11 \u4f1a\u76f4\u63a5\u5728\u8fd9\u4e2a\u6570\u5b57\u540e\u9762\u8865 0\uff0c\u751a\u81f3\u5728 toFixed(20) \u7684\u65f6\u5019\u4e5f\u662f\u8fd9\u6837\uff0c\u56e0\u4e3a\u5b83\u770b\u8d77\u6765\u5f3a\u5236\u53d6\u6574\u4e86\u503c\u6765\u51cf\u5c11\u786c\u4ef6\u9650\u5236\u5e26\u6765\u7684\u95ee\u9898\u3002<\/p>\n<p dir=\"auto\">\u8be6\u89c1 ECMA-262 \u4e2d\u00a0<code>NOTE 2<\/code>\u00a0\u7684\u00a0<code>toFixed<\/code>\u00a0\u7684\u5b9a\u4e49\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/\/#sec-number.prototype.tofixed\" rel=\"nofollow\"><strong>20.1.3.3<\/strong>\u00a0Number.prototype.toFixed (<code>fractionDigits<\/code>)<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-min-\u5927\u4e8e-max\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#min-%E5%A4%A7%E4%BA%8E-max\"><code>min<\/code>\u00a0\u5927\u4e8e\u00a0<code>max<\/code><\/a><\/h2>\n<p dir=\"auto\">\u6211\u53d1\u73b0\u4e00\u4e2a\u795e\u5947\u7684\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">min<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">max<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">min<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">max<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-50\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-50\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8fd9\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u4f8b\u5b50\u3002\u6211\u4eec\u4e00\u6b65\u4e00\u6b65\u6765\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">min<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; Infinity<\/span>\r\n<span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">max<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; -Infinity<\/span>\r\n<span class=\"pl-v\">Infinity<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">-<\/span><span class=\"pl-v\">Infinity<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4e3a\u4ec0\u4e48\u662f\u8fd9\u6837\u5462\uff1f\u5176\u5b9e\u00a0<code>Math.max()<\/code>\u00a0\u5e76\u4e0d\u4f1a\u8fd4\u56de\u6700\u5927\u7684\u6b63\u6570\uff0c\u5373\u00a0<code>Number.MAX_VALUE<\/code>\u3002<\/p>\n<p dir=\"auto\"><code>Math.max<\/code>\u00a0\u63a5\u53d7\u4e24\u4e2a\u53c2\u6570\uff0c\u5c06\u5b83\u4eec\u8f6c\u6362\u5230\u6570\u5b57\uff0c\u6bd4\u8f83\u4e4b\u540e\u8fd4\u56de\u6700\u5927\u7684\u90a3\u4e2a\u3002\u82e5\u6ca1\u6709\u4f20\u5165\u53c2\u6570\uff0c\u7ed3\u679c\u5c06\u662f -\u221e\u3002\u82e5\u53c2\u6570\u4e2d\u5b58\u5728\u00a0<code>NaN<\/code>\uff0c\u5219\u8fd4\u56de\u00a0<code>NaN<\/code>\u3002<\/p>\n<p dir=\"auto\">\u53cd\u8fc7\u6765\uff0c\u5f53\u00a0<code>Math.min<\/code>\u00a0\u6ca1\u6709\u4f20\u5165\u53c2\u6570\uff0c\u4f1a\u8fd4\u56de \u221e\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/262.ecma-international.org\/5.1\/#sec-15.8.2.11\" rel=\"nofollow\"><strong>15.8.2.11<\/strong>\u00a0Math.max<\/a><\/li>\n<li><a href=\"https:\/\/262.ecma-international.org\/5.1\/#sec-15.8.2.12\" rel=\"nofollow\"><strong>15.8.2.11<\/strong>\u00a0Math.min<\/a><\/li>\n<li><a href=\"https:\/\/charlieharvey.org.uk\/page\/why_math_max_is_less_than_math_min\" rel=\"nofollow\">\u4e3a\u4ec0\u4e48\u00a0<code>Math.max()<\/code>\u00a0\u5c0f\u4e8e\u00a0<code>Math.min()<\/code>\uff1f<\/a>##\u00a0<code>Math.max()<\/code>\u00a0\u5c0f\u4e8e\u00a0<code>Math.min()<\/code><\/li>\n<\/ul>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">min<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">7<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 1<\/span>\r\n<span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">max<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">4<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">7<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 7<\/span>\r\n<span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">min<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; Infinity<\/span>\r\n<span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">max<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; -Infinity<\/span>\r\n<span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">min<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-v\">Math<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">max<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-51\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-51\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<ul dir=\"auto\">\n<li>Charlie Harvey \u7684\u00a0<a href=\"https:\/\/charlieharvey.org.uk\/page\/why_math_max_is_less_than_math_min\" rel=\"nofollow\">Why is Math.max() less than Math.min()?<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u6bd4\u8f83-null-\u548c-0\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%AF%94%E8%BE%83-null-%E5%92%8C-0\">\u6bd4\u8f83\u00a0<code>null<\/code>\u00a0\u548c\u00a0<code>0<\/code><\/a><\/h2>\n<p dir=\"auto\">\u4e0b\u9762\u7684\u8868\u8fbe\u5f0f\u4f3c\u4e4e\u6709\u70b9\u77db\u76fe\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n<span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">&gt;=<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u65e2\u7136\u00a0<code>null &gt;= 0<\/code>\u00a0\u8fd4\u56de\u00a0<code>true<\/code>\uff0c\u4e3a\u4ec0\u4e48\u00a0<code>null<\/code>\u00a0\u65e2\u4e0d\u7b49\u4e8e\u4e5f\u4e0d\u5927\u4e8e\u00a0<code>0<\/code>\uff1f\uff08\u5bf9\u4e8e\u5c0f\u4e8e\u6bd4\u8f83\u4e5f\u53ef\u4ee5\u5f97\u51fa\u76f8\u4f3c\u7684\u7ed3\u679c\u3002\uff09<\/p>\n<h3 id=\"user-content--\u8bf4\u660e-52\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-52\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8fd9\u4e09\u4e2a\u8868\u8fbe\u5f0f\u7684\u6c42\u503c\u65b9\u5f0f\u5404\u4e0d\u76f8\u540c\uff0c\u56e0\u6b64\u4ea7\u751f\u4e86\u975e\u9884\u671f\u7684\u7ed3\u679c\u3002 \u9996\u5148\uff0c\u5bf9\u4e8e\u00a0<code>null == 0<\/code>\u00a0\u8fd9\u4e2a\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83\u64cd\u4f5c\uff0c\u901a\u5e38\u5f53\u8be5\u8fd0\u7b97\u7b26\u4e0d\u80fd\u6b63\u786e\u5730\u6bd4\u8f83\u4e24\u8fb9\u7684\u503c\uff0c\u5219\u5b83\u4f1a\u5c06\u4e24\u8fb9\u7684\u503c\u90fd\u8f6c\u6362\u4e3a\u6570\u5b57\uff0c\u518d\u5bf9\u6570\u5b57\u8fdb\u884c\u6bd4\u8f83\u3002\u90a3\u4e48\uff0c\u60a8\u53ef\u80fd\u4f1a\u671f\u671b\u4ee5\u4e0b\u884c\u4e3a\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c\">\/\/ \u4e8b\u5b9e\u5e76\u975e\u5982\u6b64<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">0<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u7136\u800c\uff0c\u4ed4\u7ec6\u9605\u8bfb\u89c4\u8303\u5c31\u4f1a\u53d1\u73b0\uff0c\u6570\u5b57\u8f6c\u6362\u5b9e\u9645\u4e0a\u5e76\u6ca1\u6709\u53d1\u751f\u5728\u00a0<code>null<\/code>\u00a0\u6216\u00a0<code>undefined<\/code>\u00a0\u7684\u4e00\u4fa7\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5982\u679c\u5728\u7b49\u53f7\u7684\u4e00\u4fa7\u6709\u00a0<code>null<\/code>\uff0c\u5219\u5f53\u53e6\u4e00\u4fa7\u7684\u8868\u8fbe\u5f0f\u4e3a\u00a0<code>null<\/code>\u00a0\u6216\u00a0<code>undefined<\/code>\u5c31\u8fd4\u56de\u00a0<code>true<\/code>\uff1b\u53cd\u4e4b\u5219\u8fd4\u56de\u00a0<code>false<\/code>\u3002<\/p>\n<p dir=\"auto\">\u63a5\u4e0b\u6765\uff0c\u5bf9\u4e8e\u00a0<code>null &gt; 0<\/code>\u00a0\u8fd9\u4e2a\u6bd4\u8f83\u5173\u7cfb\u3002\u4e0e\u62bd\u8c61\u76f8\u7b49\u8fd0\u7b97\u7b26\u7684\u7b97\u6cd5\u4e0d\u540c\uff0c\u5b83\u00a0<em>\u4f1a<\/em>\u00a0\u5148\u5c06\u00a0<code>null<\/code>\u00a0\u8f6c\u6362\u4e3a\u4e00\u4e2a\u6570\u5b57\u3002\u56e0\u6b64\uff0c\u6211\u4eec\u5f97\u5230\u8fd9\u6837\u7684\u884c\u4e3a:<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">0<\/span>\r\n<span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">0<\/span>\r\n<span class=\"pl-c1\">0<\/span> <span class=\"pl-c1\">&gt;<\/span> <span class=\"pl-c1\">0<\/span>\r\n<span class=\"pl-c1\">false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u6700\u540e\u4e00\u4e2a\uff0c\u5bf9\u4e8e\u00a0<code>null &gt;= 0<\/code>\u00a0\u7684\u6bd4\u8f83\u5173\u7cfb\u3002\u4f60\u53ef\u80fd\u8ba4\u4e3a\u8fd9\u4e2a\u8868\u8fbe\u5f0f\u5e94\u8be5\u7b49\u540c\u4e8e\u00a0<code>null &gt; 0 || null == 0<\/code>\u00a0\u7684\u7ed3\u679c\uff1b\u5982\u679c\u771f\u662f\u8fd9\u6837\uff0c\u90a3\u4e48\u57fa\u4e8e\u4e0a\u8ff0\u7684\u8ba8\u8bba\uff0c\u8fd9\u91cc\u7684\u7ed3\u679c\u4e5f\u5e94\u5f53\u662f\u00a0<code>false<\/code>\u00a0\u624d\u5bf9\u3002\u7136\u800c\uff0c<code>&gt;=<\/code>\u00a0\u64cd\u4f5c\u7b26\u7684\u5de5\u4f5c\u65b9\u5f0f\u5b9e\u9645\u4e0a\u662f\u00a0<code>&lt;<\/code>\u00a0\u64cd\u4f5c\u7b26\u7684\u53d6\u53cd\u3002\u5728\u6211\u4eec\u4e0a\u8ff0\u7684\u8ba8\u8bba\u4e2d\uff0c\u5173\u4e8e\u5927\u4e8e\u8fd0\u7b97\u7b26\u7684\u8bba\u8ff0\u4e5f\u9002\u7528\u4e8e\u5c0f\u4e8e\u8fd0\u7b97\u7b26\uff0c\u4e5f\u5c31\u662f\u8bf4\u8fd9\u4e2a\u8868\u8fbe\u5f0f\u7684\u503c\u662f\u8fd9\u6837\u51fa\u6765\u7684\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">&gt;=<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-c1\">+<\/span><span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">0<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">!<\/span><span class=\"pl-c1\">false<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-abstract-relational-comparison\" rel=\"nofollow\"><strong>7.2.12<\/strong>\u00a0\u62bd\u8c61\u5173\u7cfb\u6bd4\u8f83<\/a><\/li>\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-abstract-equality-comparison\" rel=\"nofollow\"><strong>7.2.13<\/strong>\u00a0\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83<\/a><\/li>\n<li><a href=\"https:\/\/blog.campvanilla.com\/javascript-the-curious-case-of-null-0-7b131644e274\" rel=\"nofollow\">\u4e00\u7bc7\u6df1\u5165\u6d45\u51fa\u7684\u8bf4\u660e<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u76f8\u540c\u53d8\u91cf\u91cd\u590d\u58f0\u660e\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%9B%B8%E5%90%8C%E5%8F%98%E9%87%8F%E9%87%8D%E5%A4%8D%E5%A3%B0%E6%98%8E\">\u76f8\u540c\u53d8\u91cf\u91cd\u590d\u58f0\u660e<\/a><\/h2>\n<p dir=\"auto\">JS \u5141\u8bb8\u91cd\u590d\u58f0\u660e\u53d8\u91cf\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ \u8fd9\u4e5f\u662f\u6709\u6548\u7684<\/span>\r\n<span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4e25\u683c\u6a21\u5f0f\u4e5f\u53ef\u4ee5\u8fd0\u884c\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u89e3\u91ca\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%A7%A3%E9%87%8A\">? \u89e3\u91ca\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u6240\u6709\u7684\u5b9a\u4e49\u90fd\u88ab\u5408\u5e76\u6210\u4e00\u6761\u5b9a\u4e49\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-variable-statement\" rel=\"nofollow\"><strong>13.3.2<\/strong>\u00a0\u53d8\u91cf\u8868\u8fbe\u5f0f<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-arrayprototypesort-\u7684\u9ed8\u8ba4\u884c\u4e3a\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#arrayprototypesort-%E7%9A%84%E9%BB%98%E8%AE%A4%E8%A1%8C%E4%B8%BA\">Array.prototype.sort() \u7684\u9ed8\u8ba4\u884c\u4e3a<\/a><\/h2>\n<p dir=\"auto\">\u5047\u8bbe\u4f60\u9700\u8981\u5bf9\u6570\u7ec4\u6392\u5e8f\u3002<\/p>\n<div class=\"snippet-clipboard-content notranslate position-relative overflow-auto\">\n<pre class=\"notranslate\"><code>[ 10, 1, 3 ].sort() \/\/ -&gt; [ 1, 10, 3 ]\r\n<\/code><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-53\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-53\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u9ed8\u8ba4\u7684\u6392\u5e8f\u7b97\u6cd5\u57fa\u4e8e\u5c06\u7ed9\u5b9a\u5143\u7d20\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\uff0c\u7136\u540e\u6bd4\u8f83\u5b83\u4eec\u7684 UTF-16 \u5e8f\u5217\u4e2d\u7684\u503c\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.ecma-international.org\/ecma-262\/#sec-array.prototype.sort\" rel=\"nofollow\"><strong>22.1.3.25<\/strong>\u00a0Array.prototype.sort ( comparefn )<\/a><\/li>\n<\/ul>\n<h3 id=\"user-content-\u63d0\u793a\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%8F%90%E7%A4%BA\">\u63d0\u793a<\/a><\/h3>\n<p dir=\"auto\">\u4f20\u5165\u4e00\u4e2a\u00a0<code>compareFn<\/code>\u00a0\u6bd4\u8f83\u51fd\u6570\uff0c\u5bf9\u975e\u5b57\u7b26\u4e32\u7684\u5176\u4ed6\u503c\u6392\u5e8f\u3002<\/p>\n<div class=\"snippet-clipboard-content notranslate position-relative overflow-auto\">\n<pre class=\"notranslate\"><code>[ 10, 1, 3 ].sort((a, b) =&gt; a - b) \/\/ -&gt; [ 1, 3, 10 ]\r\n<\/code><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h2 id=\"user-content-resolve-\u4e0d\u4f1a\u8fd4\u56de-promise-\u5b9e\u4f8b\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#resolve-%E4%B8%8D%E4%BC%9A%E8%BF%94%E5%9B%9E-promise-%E5%AE%9E%E4%BE%8B\">resolve() \u4e0d\u4f1a\u8fd4\u56de Promise \u5b9e\u4f8b<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">theObject<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-c1\">a<\/span>: <span class=\"pl-c1\">7<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">thePromise<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Promise<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">resolve<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">reject<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-s1\">resolve<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">theObject<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; Promise \u5b9e\u4f8b\u5bf9\u8c61<\/span>\r\n\r\n<span class=\"pl-s1\">thePromise<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">then<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-s1\">theObject<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n  <span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; { a: 7 }<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u4ece\u00a0<code>thePromise<\/code>\u00a0\u63a5\u6536\u5230\u7684\u00a0<code>value<\/code>\u00a0\u503c\u786e\u5b9e\u662f\u00a0<code>theObject<\/code>\u3002<\/p>\n<p dir=\"auto\">\u90a3\u4e48\uff0c\u5982\u679c\u5411\u00a0<code>resolve<\/code>\u00a0\u4f20\u5165\u53e6\u5916\u4e00\u4e2a\u00a0<code>Promise<\/code>\u00a0\u4f1a\u600e\u6837\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">theObject<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Promise<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">resolve<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">reject<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-s1\">resolve<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">7<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; Promise \u5b9e\u4f8b\u5bf9\u8c61<\/span>\r\n<span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">thePromise<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Promise<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">resolve<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">reject<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-s1\">resolve<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">theObject<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; Promise \u5b9e\u4f8b\u5bf9\u8c61<\/span>\r\n\r\n<span class=\"pl-s1\">thePromise<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">then<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-s1\">theObject<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span>\r\n  <span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 7<\/span>\r\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-54\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-54\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<blockquote>\n<p dir=\"auto\">\u6b64\u51fd\u6570\u5c06\u7c7b promise \u5bf9\u8c61\u7684\u591a\u5c42\u5d4c\u5957\u5e73\u94fa\u5230\u5355\u5c42\u5d4c\u5957\u3002\uff08\u4f8b\u5982\u4e0a\u8ff0\u7684 promise \u51fd\u6570 resolve \u4e86\u53e6\u4e00\u4e2a\u4f1a resolve \u51fa\u5176\u4ed6\u5bf9\u8c61\u7684 promise \u51fd\u6570\uff09<\/p>\n<\/blockquote>\n<p dir=\"auto\">\u2013\u00a0<a href=\"https:\/\/developer.mozilla.org\/zh-CN\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Promise\/resolve\" rel=\"nofollow\">MDN \u4e0a\u7684 Promise.resolve()<\/a><\/p>\n<p dir=\"auto\">\u5b98\u65b9\u89c4\u8303\u662f\u00a0<a href=\"https:\/\/tc39.es\/ecma262\/#sec-promise-resolve-functions\" rel=\"nofollow\">ECMAScript 25.6.1.3.2 Promise \u7684 Resolve \u51fd\u6570<\/a>\uff0c\u4f46\u662f\u8fd9\u4e00\u7ae0\u8282\u5bf9\u4eba\u7c7b\u975e\u5e38\u4e0d\u53cb\u597d\u3002<\/p>\n<h2 id=\"user-content--\u662f-undefined\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E6%98%AF-undefined\"><code>{}{}<\/code>\u00a0\u662f undefined<\/a><\/h2>\n<p dir=\"auto\">\u4f60\u53ef\u4ee5\u5728\u7ec8\u7aef\u6d4b\u8bd5\u4e00\u4e0b\u3002\u7c7b\u4f3c\u8fd9\u6837\u7684\u7ed3\u6784\u4f1a\u8fd4\u56de\u6700\u540e\u5b9a\u4e49\u7684\u5bf9\u8c61\u4e2d\u7684\u503c\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; undefined<\/span>\r\n<span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; undefined<\/span>\r\n<span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; undefined<\/span>\r\n<span class=\"pl-kos\">{<\/span>foo: <span class=\"pl-s\">'bar'<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'bar'<\/span>\r\n<span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-c1\">foo<\/span>: <span class=\"pl-s\">'bar'<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'bar'<\/span>\r\n<span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span>foo: <span class=\"pl-s\">'bar'<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'bar'<\/span>\r\n<span class=\"pl-kos\">{<\/span>a: <span class=\"pl-s\">'b'<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span>c:<span class=\"pl-s\">' d'<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'd'<\/span>\r\n<span class=\"pl-kos\">{<\/span><span class=\"pl-c1\">a<\/span>: <span class=\"pl-s\">'b'<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">c<\/span>: <span class=\"pl-s\">'d'<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ &gt; SyntaxError: Unexpected token ':'<\/span>\r\n<span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ &gt; SyntaxError: Unexpected token '{'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-55\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-55\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u89e3\u6790\u5230\u00a0<code>{}<\/code>\u00a0\u4f1a\u8fd4\u56de\u00a0<code>undefined<\/code>\uff0c\u800c\u89e3\u6790\u00a0<code>{foo: 'bar'}{}<\/code>\u65f6\uff0c\u8868\u8fbe\u5f0f\u00a0<code>{foo: 'bar'}<\/code>\u00a0\u8fd4\u56de\u00a0<code>'bar'<\/code>\u3002<\/p>\n<p dir=\"auto\"><code>{}<\/code>\u00a0\u6709\u4e24\u91cd\u542b\u4e49\uff1a\u8868\u793a\u5bf9\u8c61\uff0c\u6216\u8868\u793a\u4ee3\u7801\u5757\u3002\u4f8b\u5982\uff0c\u5728\u00a0<code>() =&gt; {}<\/code>\u00a0\u4e2d\u7684\u00a0<code>{}<\/code>\u00a0\u8868\u793a\u4ee3\u7801\u5757\u3002\u6240\u4ee5\u6211\u4eec\u5fc5\u987b\u52a0\u4e0a\u62ec\u53f7\uff1a<code>() =&gt; ({})<\/code>\u00a0\u624d\u80fd\u8ba9\u5b83\u6b63\u786e\u5730\u8fd4\u56de\u4e00\u4e2a\u5bf9\u8c61\u3002<\/p>\n<p dir=\"auto\">\u56e0\u6b64\uff0c\u6211\u4eec\u73b0\u5728\u5c06\u00a0<code>{foo: 'bar'}<\/code>\u00a0\u5f53\u4f5c\u4ee3\u7801\u5757\u4f7f\u7528\uff0c\u5219\u53ef\u4ee5\u5728\u7ec8\u7aef\u4e2d\u8fd9\u6837\u5199\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  foo: <span class=\"pl-s\">\"bar\"<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span> <span class=\"pl-c\">\/\/ -&gt; 'bar'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u554a\u54c8\uff0c\u4e00\u6837\u7684\u7ed3\u679c\uff01\u6240\u4ee5\u00a0<code>{foo: 'bar'}{}<\/code>\u00a0\u4e2d\u7684\u82b1\u62ec\u53f7\u5c31\u662f\u8868\u793a\u4ee3\u7801\u5757\u3002<\/p>\n<h2 id=\"user-content-arguments-\u7ed1\u5b9a\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#arguments-%E7%BB%91%E5%AE%9A\"><code>arguments<\/code>\u00a0\u7ed1\u5b9a<\/a><\/h2>\n<p dir=\"auto\">\u8003\u8651\u4ee5\u4e0b\u51fd\u6570\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">function<\/span> <span class=\"pl-en\">a<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">x<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-smi\">arguments<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"hello\"<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">x<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span>\r\n\r\n<span class=\"pl-en\">a<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ &gt; undefined<\/span>\r\n<span class=\"pl-en\">a<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ &gt; \"hello\"<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-56\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-56\">? \u8bf4\u660e<\/a><\/h3>\n<p dir=\"auto\"><code>arguments<\/code>\u00a0\u662f\u4e00\u4e2a\u7c7b\u6570\u7ec4\u5bf9\u8c61\uff0c\u5305\u542b\u4e86\u6240\u6709\u4f20\u5165\u5f53\u524d\u51fd\u6570\u7684\u53c2\u6570\u3002\u5f53\u6ca1\u6709\u4f20\u5165\u53c2\u6570\u65f6\uff0c\u8be5\u5bf9\u8c61\u4e2d\u5c31\u4e0d\u5b58\u5728\u00a0<code>x<\/code>\u00a0\u5c5e\u6027\uff0c\u4e5f\u5c31\u65e0\u6cd5\u8986\u76d6\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Functions\/arguments\" rel=\"nofollow\">arguments \u5bf9\u8c61<\/a>\u00a0on MDN<\/li>\n<\/ul>\n<h2 id=\"user-content-\u6765\u81ea\u5730\u72f1\u7684-alert\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%9D%A5%E8%87%AA%E5%9C%B0%E7%8B%B1%E7%9A%84-alert\">\u6765\u81ea\u5730\u72f1\u7684\u00a0<code>alert<\/code><\/a><\/h2>\n<p dir=\"auto\">\u5982\u9898\uff0c\u4ece\u5730\u72f1\u800c\u6765\u7684\u4ee3\u7801\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">666<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s\">\"\\155\\141\\160\"<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s\">\"\\143\\157\\156\\163\\164\\162\\165\\143\\164\\157\\162\"<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">(<\/span>\r\n  <span class=\"pl-s\">\"\\141\\154\\145\\162\\164(666)\"<\/span>\r\n<span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">666<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ alert(666)<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-57\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-57\">? \u8bf4\u660e<\/a><\/h3>\n<p dir=\"auto\">\u8fd9\u4e00\u4e32\u4ee3\u7801\u662f\u57fa\u4e8e\u591a\u4e2a\u91c7\u7528\u4e86\u516b\u8fdb\u5236\u8f6c\u4e49\u5e8f\u5217\u7684\u5b57\u7b26\u4e32\u6784\u9020\u7684\u3002<\/p>\n<p dir=\"auto\">\u4efb\u4f55\u7801\u503c\u5c0f\u4e8e 256 \u7684\u5b57\u7b26\uff08\u53c8\u79f0\u6269\u5c55 ASCII \u7801\u8868\u57df\uff09\u90fd\u53ef\u4ee5\u7528\u00a0<code>\\<\/code>\u00a0\u52a0\u4e0a\u5176\u516b\u8fdb\u5236\u4ee3\u7801\u7684\u8f6c\u4e49\u65b9\u5f0f\u5199\u51fa\u6765\u3002\u4e0a\u9762\u8fd9\u4e2a\u7b80\u5355\u7684\u4f8b\u5b50\u5c31\u662f\u5c06\u00a0<code>alert<\/code>\u00a0\u7f16\u7801\u5230\u516b\u8fdb\u5236\u8f6c\u4e49\u5e8f\u5217\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/twitter.com\/aemkei\/status\/897172907222237185\" rel=\"nofollow\">Martin Kleppe \u7684\u63a8\u7279<\/a><\/li>\n<li><a href=\"https:\/\/mathiasbynens.be\/notes\/javascript-escapes#octal\" rel=\"nofollow\">JavaScript \u5b57\u7b26\u8f6c\u4e49\u5e8f\u5217<\/a><\/li>\n<li><a href=\"https:\/\/davidwalsh.name\/multiline-javascript-strings\" rel=\"nofollow\">\u591a\u884c JavaScript \u5b57\u7b26\u4e32<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u6ca1\u6709\u5c3d\u5934\u7684\u8ba1\u65f6\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E6%B2%A1%E6%9C%89%E5%B0%BD%E5%A4%B4%E7%9A%84%E8%AE%A1%E6%97%B6\">\u6ca1\u6709\u5c3d\u5934\u7684\u8ba1\u65f6<\/a><\/h2>\n<p dir=\"auto\">\u5982\u679c\u6211\u4eec\u5bf9\u00a0<code>setTimeout<\/code>\u00a0\u8d4b\u4e88\u65e0\u9650\u5927\u4f1a\u5982\u4f55\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">setTimeout<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"called\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-v\">Infinity<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; &lt;timeoutId&gt;<\/span>\r\n<span class=\"pl-c\">\/\/ &gt; 'called'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u7ed3\u679c\u662f\uff0c\u5b83\u4f1a\u7acb\u5373\u8fd0\u884c\uff0c\u5e76\u6ca1\u6709\u7b49\u5f85\u65e0\u9650\u957f\u7684\u65f6\u95f4\u3002<\/p>\n<h3 id=\"user-content--\u8bf4\u660e-58\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-58\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u901a\u5e38\u8fd0\u884c\u65f6\u5185\u90e8\u4f1a\u5c06\u5ef6\u65f6\u5b58\u50a8\u4e3a\u4e00\u4e2a 32 \u4f4d\u7684\u6709\u7b26\u53f7\u6574\u6570\uff0c\u800c\u4e0a\u8ff0\u4ee3\u7801\u4f1a\u5bfc\u81f4\u8fd0\u884c\u65f6\u5728\u89e3\u6790\u5ef6\u65f6\u53c2\u6570\u65f6\u53d1\u751f\u6574\u6570\u6ea2\u51fa\uff0c\u4ece\u800c\u4f7f\u51fd\u6570\u7acb\u5373\u6267\u884c\u800c\u4e0d\u7b49\u5f85\u3002<\/p>\n<p dir=\"auto\">\u4f8b\u5982\uff0c\u5728 Node.js \u4e2d\u6211\u4eec\u53ef\u4ee5\u770b\u5230\u8fd9\u6837\u7684\u8b66\u544a\u4fe1\u606f\uff1a<\/p>\n<div class=\"snippet-clipboard-content notranslate position-relative overflow-auto\">\n<pre class=\"notranslate\"><code>(node:1731) TimeoutOverflowWarning: Infinity does not fit into a 32-bit signed integer.\r\nTimeout duration was set to 1.\r\n(Use `node --trace-warnings ...` to show where the warning was created)\r\n<\/code><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/API\/WindowOrWorkerGlobalScope\/setTimeout\" rel=\"nofollow\">WindowOrWorkerGlobalScope.setTimeout()<\/a>\u00a0on MDN<\/li>\n<li><a href=\"https:\/\/nodejs.org\/api\/timers.html#timers_settimeout_callback_delay_args\" rel=\"nofollow\">Node.js \u6587\u6863\u4e2d\u5173\u4e8e\u8ba1\u65f6\u5668\u7684\u7ae0\u8282<\/a><\/li>\n<li>W3C \u4e0a\u7684 [\u8ba1\u65f6\u5668]](<a href=\"https:\/\/www.w3.org\/TR\/2011\/WD-html5-20110525\/timers.html\" rel=\"nofollow\">https:\/\/www.w3.org\/TR\/2011\/WD-html5-20110525\/timers.html<\/a>)<\/li>\n<\/ul>\n<h2 id=\"user-content-settimeout-\u5bf9\u8c61\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#settimeout-%E5%AF%B9%E8%B1%A1\"><code>setTimeout<\/code>\u00a0\u5bf9\u8c61<\/a><\/h2>\n<p dir=\"auto\">\u5982\u679c\u6211\u4eec\u7ed9\u00a0<code>setTimeout<\/code>\u00a0\u7684\u56de\u8c03\u51fd\u6570\u53c2\u6570\u4f20\u975e\u51fd\u6570\u503c\u4f1a\u53d1\u751f\u4ec0\u4e48\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">setTimeout<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">123<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">100<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; &lt;timeoutId&gt;<\/span>\r\n<span class=\"pl-c\">\/\/ &gt; 'called'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u6ca1\u95ee\u9898\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">setTimeout<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">'{a: 1}'<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">100<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; &lt;timeoutId&gt;<\/span>\r\n<span class=\"pl-c\">\/\/ &gt; 'called'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u8fd9\u4e2a\u4e5f\u6ca1\u95ee\u9898\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">setTimeout<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-c1\">a<\/span>: <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">100<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; &lt;timeoutId&gt;<\/span>\r\n<span class=\"pl-c\">\/\/ &gt; 'Uncaught SyntaxError: Unexpected identifier               setTimeout (async) (anonymous) @ VM__:1'<\/span>\r\n<span class=\"pl-c\">\/\/ \u672a\u6355\u83b7\u7684\u8bed\u6cd5\u9519\u8bef\uff1a\u975e\u9884\u671f\u7684\u6807\u8bc6\u7b26<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u629b\u51fa\u4e86\u4e00\u4e2a\u00a0<strong>SyntaxError<\/strong>\uff08\u8bed\u6cd5\u9519\u8bef\uff09\u3002<\/p>\n<p dir=\"auto\">\u8fd9\u79cd\u9519\u8bef\u5f88\u5bb9\u6613\u53d1\u751f\uff0c\u5c24\u5176\u662f\u5f53\u4f60\u6709\u4e2a\u51fd\u6570\u8fd4\u56de\u4e00\u4e2a\u5bf9\u8c61\uff0c\u4f46\u662f\u4f60\u5fd8\u4e86\u5c06\u5176\u4f20\u8fdb\u51fd\u6570\uff0c\u76f4\u63a5\u5c31\u5728\u8fd9\u91cc\u8c03\u7528\u4e86\uff01\u4e0d\u8fc7\uff0c\u5982\u679c\u00a0<code>content-policy<\/code>\u00a0\u8bbe\u7f6e\u4e3a\u00a0<code>self<\/code>\u00a0\u4f1a\u600e\u4e48\u6837\u5462\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-en\">setTimeout<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">123<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">100<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; &lt;timeoutId&gt;<\/span>\r\n<span class=\"pl-c\">\/\/ &gt; console.error(\"[Report Only] Refused to evaluate a string as JavaScript because 'unsafe-eval' is not an allowed source of script in the following Content Security Policy directive: \"script-src 'report-sample' 'self' \")<\/span>\r\n<span class=\"pl-c\">\/\/ [\u4ec5\u62a5\u544a] \u62d2\u7edd\u5c06\u5b57\u7b26\u4e32\u5f53\u4f5cJavaScript\u6c42\u503c\uff0c\u56e0\u4e3a\u5185\u5bb9\u5b89\u5168\u7b56\u7565\uff08CSP\uff0cContent Security Policy\uff09\u6307\u4ee4\u88ab\u8bbe\u7f6e\u4e3a \"script-src 'report-sample' 'self'\"\uff0c\u5728\u8be5\u6307\u4ee4\u6a21\u5f0f\u4e0b\u4e0d\u5141\u8bb8 'unsafe-eval' \u7684\u811a\u672c\u6e90\u3002<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u7ec8\u7aef\u4f1a\u62d2\u7edd\u6267\u884c\uff01<\/p>\n<h3 id=\"user-content--\u8bf4\u660e-59\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-59\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\"><code>WindowOrWorkerGlobalScope.setTimeout()<\/code>\u00a0\u7684\u7b2c\u4e00\u4e2a\u53c2\u6570\u53ef\u4ee5\u662f\u4ee3\u7801\uff08<code>code<\/code>\uff09\uff0c\u4ee3\u7801\u4f1a\u88ab\u4f20\u9012\u5230\u00a0<code>eval<\/code>\u00a0\u51fd\u6570\uff0c\u8fd9\u662f\u4e0d\u597d\u7684\u3002<code>eval<\/code>\u00a0\u4f1a\u628a\u6240\u6709\u8f93\u5165\u5f3a\u5236\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\uff0c\u7136\u540e\u8fdb\u884c\u6c42\u503c\uff0c\u90a3\u4e48\u5bf9\u8c61\u4f1a\u53d8\u6210\u00a0<code>'[object Object]'<\/code>\uff1b\u55ef\uff0c\u4f60\u4e5f\u770b\u5230\u4e86\uff0c\u8fd9\u91cc\u786e\u5b9e\u6709\u4e00\u4e2a\u975e\u6cd5\u6807\u8bc6\u7b26\u00a0<code>'Unexpected identifier'<\/code>\u3002<\/p>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/eval\" rel=\"nofollow\">eval()<\/a>\u00a0on MDN (don&#8217;t use this)<\/li>\n<li><a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/API\/WindowOrWorkerGlobalScope\/setTimeout\" rel=\"nofollow\">WindowOrWorkerGlobalScope.setTimeout()<\/a>\u00a0on MDN<\/li>\n<li><a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/HTTP\/Headers\/Content-Security-Policy\" rel=\"nofollow\">\u5185\u5bb9\u5b89\u5168\u7b56\u7565<\/a><\/li>\n<li>W3C \u4e0a\u7684\u00a0<a href=\"https:\/\/www.w3.org\/TR\/2011\/WD-html5-20110525\/timers.html\" rel=\"nofollow\">\u8ba1\u65f6\u5668<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u70b9\u70b9\u8fd0\u7b97\u7b26\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%82%B9%E7%82%B9%E8%BF%90%E7%AE%97%E7%AC%A6\">\u70b9\u70b9\u8fd0\u7b97\u7b26<\/a><\/h2>\n<p dir=\"auto\">\u73b0\u5728\u5c1d\u8bd5\u628a\u4e00\u4e2a\u6570\u5b57\u8f6c\u6362\u5230\u5b57\u7b26\u4e32\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">27.<\/span><span class=\"pl-en\">toString<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c\">\/\/ &gt; Uncaught SyntaxError: Invalid or unexpected token<\/span>\r\n<span class=\"pl-c\">\/\/ \u672a\u6355\u83b7\u7684\u8bed\u6cd5\u9519\u8bef\uff1a\u975e\u6cd5\u6216\u975e\u9884\u671f\u7684\u8bcd\u5143\uff08token\uff09<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u5982\u679c\u6211\u4eec\u518d\u52a0\u4e0a\u4e00\u4e2a\u70b9\u5462\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">27.<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toString<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; '27'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u90a3\u4e3a\u4ec0\u4e48\u7b2c\u4e00\u4e2a\u4f8b\u5b50\u9519\u4e86\u5462\uff1f<\/p>\n<h3 id=\"user-content--\u8bf4\u660e-60\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-60\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8fd9\u662f\u6587\u6cd5\u7684\u9650\u5236\u3002<\/p>\n<p dir=\"auto\"><code>.<\/code>\u00a0\u8fd0\u7b97\u7b26\u5b58\u5728\u6b67\u4e49\uff0c\u5b83\u65e2\u53ef\u4ee5\u5f53\u5c5e\u6027\u8bbf\u95ee\u7b26\uff0c\u4e5f\u53ef\u4ee5\u662f\u5c0f\u6570\u70b9\uff0c\u8fd9\u53d6\u51b3\u4e8e\u5b83\u5728\u4ee3\u7801\u4e2d\u7684\u4f4d\u7f6e\u3002<\/p>\n<p dir=\"auto\">\u89c4\u8303\u4e2d\u5b9a\u4e49\u4e86\u00a0<code>.<\/code>\u00a0\u8fd0\u7b97\u7b26\u4ec5\u5728\u7279\u5b9a\u7684\u4f4d\u7f6e\u4f7f\u7528\u65f6\u4f1a\u88ab\u5f53\u4f5c\u5c0f\u6570\u70b9\uff0c\u8fd9\u4e2a\u5b9a\u4e49\u5199\u5728 ECMAScript \u7684\u6570\u5b57\u5b57\u9762\u91cf\u8bed\u6cd5\u4e00\u8282\u4e2d\u3002<\/p>\n<p dir=\"auto\">\u6240\u4ee5\uff0c\u5f53\u4f60\u60f3\u8981\u5728\u6570\u5b57\u540e\u52a0\u5c5e\u6027\u8bbf\u95ee\u5668\u7684\u70b9\u53f7\u65f6\uff0c\u5e94\u5f53\u52a0\u4e0a\u62ec\u53f7\uff0c\u6216\u518d\u52a0\u4e0a\u4e00\u4e2a\u70b9\uff0c\u4ee5\u4f7f\u8be5\u8868\u8fbe\u5f0f\u5408\u6cd5\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">27<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toString<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; '27'<\/span>\r\n<span class=\"pl-c\">\/\/ or<\/span>\r\n<span class=\"pl-c1\">27.<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toString<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; '27'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/stackoverflow.com\/questions\/6853865\/usage-of-tostring-in-javascript\/6853910#6853910\" rel=\"nofollow\">JavaScript \u4e2d toString \u7684\u7528\u6cd5<\/a>\u00a0on StackOverflow<\/li>\n<li><a href=\"https:\/\/stackoverflow.com\/questions\/13149282\/why-does-10-tostring-work-but-10-tostring-does-not\/13149301#13149301\" rel=\"nofollow\">\u4e3a\u4ec0\u4e48 10..toString() \u53ef\u884c\uff0c\u800c 10.toString() \u5374\u4e0d\u884c\uff1f<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u518d-new-\u4e00\u6b21\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%86%8D-new-%E4%B8%80%E6%AC%A1\">\u518d new \u4e00\u6b21<\/a><\/h2>\n<p dir=\"auto\">\u8fd9\u4ec5\u4ec5\u662f\u4e00\u4e2a\u7528\u4e8e\u5a31\u4e50\u7684\u4f8b\u5b50\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">class<\/span> <span class=\"pl-v\">Foo<\/span> <span class=\"pl-k\">extends<\/span> <span class=\"pl-v\">Function<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-en\">constructor<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">val<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n    <span class=\"pl-smi\">super<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n    <span class=\"pl-smi\">this<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">prototype<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">val<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">val<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-kos\">}<\/span>\r\n\r\n<span class=\"pl-k\">new<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Foo<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\":D\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">val<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; ':D'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-61\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-61\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">JavaScript \u4e0e\u5176\u4ed6\u9762\u5411\u5bf9\u8c61\u8bed\u8a00\u4e0d\u540c\uff0c\u5b83\u7684\u6784\u9020\u51fd\u6570\u4ec5\u662f\u4e00\u4e2a\u6bd4\u8f83\u7279\u6b8a\u7684\u51fd\u6570\u3002\u867d\u7136 class \u8bed\u6cd5\u7cd6\u8ba9\u4f60\u53ef\u4ee5\u521b\u5efa\u4e00\u4e2a\u5b57\u9762\u4e0a\u7684\u7c7b\uff0c\u4f46\u5b9e\u4f8b\u5316\u540e\u5b83\u5c31\u53d8\u6210\u4e86\u51fd\u6570\uff0c\u56e0\u6b64\u5b83\u53ef\u4ee5\u518d\u6b21\u5b9e\u4f8b\u5316\u3002<\/p>\n<p dir=\"auto\">\u867d\u7136\u6211\u6ca1\u6709\u6d4b\u8bd5\u8fc7\uff0c\u4f46\u6211\u89c9\u5f97\u6700\u540e\u7684\u90a3\u4e2a\u8868\u8fbe\u5f0f\u5e94\u8be5\u662f\u8fd9\u6837\u5206\u6790\u7684\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">new<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Foo<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\":D\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">val<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">new<\/span> <span class=\"pl-s1\">newFooInstance<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">val<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-s1\">veryNewFooInstance<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">val<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c\">\/\/ -&gt; ':D'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u518d\u8865\u5145\u4e00\u4e0b\uff0c\u8fd0\u884c\u00a0<code>new Function('return \"bar\";')<\/code>\u00a0\u5fc5\u7136\u4f1a\u521b\u5efa\u4e00\u4e2a\u5185\u5bb9\u4e3a\u00a0<code>return \"bar\";<\/code>\u00a0\u7684\u51fd\u6570\u5bf9\u8c61\u3002\u800c<code>Foo<\/code>\u7c7b\u7684\u6784\u9020\u51fd\u6570\u4e2d\u7684\u00a0<code>super()<\/code>\u00a0\u8c03\u7528\u7684\u662f\u00a0<code>Function<\/code>\u00a0\u7684\u6784\u9020\u51fd\u6570\uff0c\u6240\u4ee5\u81ea\u7136\u800c\u7136\u6211\u4eec\u53ef\u4ee5\u5728\u5b83\u4e0a\u9762\u6dfb\u52a0\u66f4\u591a\u7684\u64cd\u4f5c\u3002<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">class<\/span> <span class=\"pl-v\">Foo<\/span> <span class=\"pl-k\">extends<\/span> <span class=\"pl-v\">Function<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-en\">constructor<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">val<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\r\n    <span class=\"pl-smi\">super<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">`<\/span>\r\n<span class=\"pl-s\">      this.val = arguments[0];<\/span>\r\n<span class=\"pl-s\">    `<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n    <span class=\"pl-smi\">this<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">prototype<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">val<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">val<\/span><span class=\"pl-kos\">;<\/span>\r\n  <span class=\"pl-kos\">}<\/span>\r\n<span class=\"pl-kos\">}<\/span>\r\n\r\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">foo<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Foo<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\":D\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"D:\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-s1\">foo<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">val<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'D:'<\/span>\r\n<span class=\"pl-k\">delete<\/span> <span class=\"pl-s1\">foo<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">val<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ \u79fb\u9664\u8fd9\u4e2a\u5b9e\u4f8b\u7684\u201cval\u201d\u5c5e\u6027\uff0c\u8ba9\u5b83\u9000\u56de\uff08defer back\uff09\u5230\u4ed6\u7684\u539f\u578b\u7684\u201cval\u201d\u5c5e\u6027<\/span>\r\n<span class=\"pl-s1\">foo<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">val<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; ':D'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/issues\/78\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/denysdovhan\/wtfjs\/issues\/78\/hovercard\">\u6269\u5c55 Function \u7684\u7c7b\uff1a\u518d new \u4e00\u6b21<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u4f60\u5e94\u8be5\u7528\u4e0a\u5206\u53f7\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E4%BD%A0%E5%BA%94%E8%AF%A5%E7%94%A8%E4%B8%8A%E5%88%86%E5%8F%B7\">\u4f60\u5e94\u8be5\u7528\u4e0a\u5206\u53f7<\/a><\/h2>\n<p dir=\"auto\">\u4e0b\u9762\u8fd9\u4e2a\u5e94\u8be5\u662f\u6807\u51c6\u7684 JavaScript\u2026\u2026\u5427\uff1f\u4e0d\uff0c\u5b83\u70b8\u4e86\uff01<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">class<\/span> <span class=\"pl-v\">SomeClass<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-kos\">[<\/span><span class=\"pl-s\">\"array\"<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span>\r\n  <span class=\"pl-kos\">[<\/span><span class=\"pl-s\">\"string\"<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"str\"<\/span>\r\n<span class=\"pl-kos\">}<\/span>\r\n\r\n<span class=\"pl-k\">new<\/span> <span class=\"pl-v\">SomeClass<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">array<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; 'str'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">woc\u2026\u2026\uff1f<\/p>\n<h3 id=\"user-content--\u8bf4\u660e-62\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-62\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u55ef\uff0c\u4f60\u6ca1\u731c\u9519\uff0c\u8fd9\u53c8\u662f\u81ea\u52a8\u5206\u53f7\u63d2\u5165\u7684\u529f\u52b3\u3002<\/p>\n<p dir=\"auto\">\u4e0a\u9762\u8fd9\u4e2a\u4f8b\u5b50\u5b9e\u9645\u4e0a\u4f1a\u88ab\u8f6c\u6362\u4e3a\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-k\">class<\/span> <span class=\"pl-v\">SomeClass<\/span> <span class=\"pl-kos\">{<\/span>\r\n  <span class=\"pl-kos\">[<\/span><span class=\"pl-s\">\"array\"<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s\">\"string\"<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">\"str\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-kos\">}<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u770b\u5230\u4e86\u5427\uff0c<code>str<\/code>\u00a0\u8fd9\u4e2a\u5b57\u7b26\u4e32\u88ab\u8d4b\u503c\u5230\u5c5e\u6027\u00a0<code>array<\/code>\u00a0\u4e0a\u3002<\/p>\n<ul dir=\"auto\">\n<li>Ryan Cavanaugh \u53d1\u5e03\u7684\u00a0<a href=\"https:\/\/twitter.com\/SeaRyanC\/status\/1148726605222535168\" rel=\"nofollow\">\u5173\u4e8e\u8fd9\u4e2a\u4f8b\u5b50\u7684\u539f\u521b\u63a8\u7279<\/a><\/li>\n<li><a href=\"https:\/\/github.com\/tc39\/notes\/blob\/master\/meetings\/2017-09\/sept-26.md\">TC39 \u4f1a\u8bae\u4e2d\u5173\u4e8e\u5b83\u7684\u8ba8\u8bba<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u7528\u7a7a\u683c\u5206\u5272split\u5b57\u7b26\u4e32\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E7%94%A8%E7%A9%BA%E6%A0%BC%E5%88%86%E5%89%B2split%E5%AD%97%E7%AC%A6%E4%B8%B2\">\u7528\u7a7a\u683c\u5206\u5272\uff08split\uff09\u5b57\u7b26\u4e32<\/a><\/h2>\n<p dir=\"auto\">\u4f60\u8bd5\u8fc7\u7528\u7a7a\u683c\u5206\u5272\u5b57\u7b26\u4e32\u5417\uff1f<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-s\">\"\"<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">split<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; []<\/span>\r\n<span class=\"pl-c\">\/\/ \u4f46\u662f\u2026\u2026<\/span>\r\n<span class=\"pl-s\">\"\"<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">split<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\" \"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; [\"\"]<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-63\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-63\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u8fd9\u662f\u9884\u671f\u884c\u4e3a\u3002\u5b83\u4f1a\u5728\u8f93\u5165\u7684\u5b57\u7b26\u4e32\u4e2d\u904d\u5386\uff0c\u4e00\u65e6\u53d1\u73b0\u5206\u9694\u7b26\uff0c\u5c31\u5728\u6b64\u5904\u5206\u5272\u3002\u4f46\u82e5\u4f60\u4f20\u5165\u7684\u662f\u7a7a\u5b57\u7b26\u4e32\uff0c\u5b83\u627e\u4e0d\u5230\u5206\u9694\u7b26\uff0c\u56e0\u6b64\u8fd4\u56de\u8be5\u5b57\u7b26\u4e32\u3002<\/p>\n<p dir=\"auto\">\u89c4\u8303\u5f15\u7528\u5982\u4e0b\uff1a<\/p>\n<blockquote>\n<p dir=\"auto\">\u5b83\u4f1a\u4ece\u5de6\u5411\u53f3\u641c\u7d22\u5b57\u7b26\u4e32\uff0c\u5e76\u6839\u636e\u00a0<code>separator<\/code>\uff08\u5206\u9694\u7b26\uff09\u51b3\u5b9a\u5b50\u5b57\u7b26\u4e32\u7684\u5206\u5272\u4f4d\u7f6e\uff1b\u5206\u5272\u4f4d\u7f6e\u7684\u5b57\u7b26\u4ec5\u7528\u4e8e\u5206\u5272\uff0c\u4e0d\u4f1a\u5305\u542b\u5728\u8fd4\u56de\u7684\u6570\u7ec4\u4e2d\u3002<\/p>\n<\/blockquote>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/tc39.es\/ecma262\/#sec-string.prototype.split\" rel=\"nofollow\"><strong>22.1.3.21<\/strong>\u00a0String.prototype.split<\/a><\/li>\n<li>Ryan Cavanaugh \u53d1\u5e03\u7684\u00a0<a href=\"https:\/\/twitter.com\/SeaRyanC\/status\/1331656278104440833\" rel=\"nofollow\">\u5173\u4e8e\u8fd9\u4e2a\u4f8b\u5b50\u7684\u539f\u521b\u63a8\u7279<\/a><\/li>\n<li>Nabil Tharwat \u53d1\u5e03\u7684\u00a0<a href=\"https:\/\/twitter.com\/kl13nt\/status\/1331742810932916227?s=20\" rel=\"nofollow\">\u5305\u542b\u89e3\u91ca\u7684\u63a8\u7279<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u5bf9\u5b57\u7b26\u4e32-stringify\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%AF%B9%E5%AD%97%E7%AC%A6%E4%B8%B2-stringify\">\u5bf9\u5b57\u7b26\u4e32 stringify<\/a><\/h2>\n<p dir=\"auto\">\u8fd9\u4f1a\u5bfc\u81f4\u4e00\u4e2a\u7f3a\u9677\uff0c\u6211\u66fe\u7ecf\u4fee\u4e86\u597d\u51e0\u5929\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">JSON<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">stringify<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"production\"<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-s\">\"production\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-64\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-64\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u5148\u770b\u770b\u00a0<code>JSON.stringify<\/code>\u00a0\u7684\u8fd4\u56de\u503c\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">JSON<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">stringify<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">\"production\"<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; '\"production\"'<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<p dir=\"auto\">\u539f\u6765\u662f\u88ab\u201c\u5b57\u4e32\u5316\u201d\u4e86\uff0c\u6240\u4ee5\u8fd9\u4e5f\u96be\u602a\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-s\">'\"production\"'<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-s\">\"production\"<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/www.json.org\/json-en.html\" rel=\"nofollow\">ECMA-404 JSON \u6570\u636e\u5185\u90e8\u53d8\u52a8\u6807\u51c6<\/a><\/li>\n<\/ul>\n<h2 id=\"user-content-\u5bf9\u6570\u5b57\u548c-true-\u7684\u975e\u4e25\u683c\u76f8\u7b49\u6bd4\u8f83\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%AF%B9%E6%95%B0%E5%AD%97%E5%92%8C-true-%E7%9A%84%E9%9D%9E%E4%B8%A5%E6%A0%BC%E7%9B%B8%E7%AD%89%E6%AF%94%E8%BE%83\">\u5bf9\u6570\u5b57\u548c\u00a0<code>true<\/code>\u00a0\u7684\u975e\u4e25\u683c\u76f8\u7b49\u6bd4\u8f83<\/a><\/h2>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">1<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-c\">\/\/ \u4f46\u662f\u2026\u2026<\/span>\r\n<span class=\"pl-v\">Boolean<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">1.1<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-c1\">1.1<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<h3 id=\"user-content--\u8bf4\u660e-65\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AF%B4%E6%98%8E-65\">? \u8bf4\u660e\uff1a<\/a><\/h3>\n<p dir=\"auto\">\u6839\u636e\u89c4\u8303\uff1a<\/p>\n<blockquote>\n<p dir=\"auto\">\u6bd4\u8f83 x == y \u65f6\uff0c\u5f53 x \u548c y \u90fd\u6709\u503c\uff0c\u4f1a\u8fd4\u56de true \u6216 false\u3002\u6bd4\u8f83\u8fc7\u7a0b\u5982\u4e0b\u6240\u8ff0\uff1a<\/p>\n<ol dir=\"auto\" start=\"4\">\n<li>\u82e5\u00a0<code>Type(x)<\/code>\u00a0\u662f\u6570\u5b57\u4e14\u00a0<code>Type(y)<\/code>\u00a0\u662f\u5b57\u7b26\u4e32\uff0c\u5219\u4f1a\u8fd4\u56de\u00a0<code>x == ! ToNumber(y)<\/code>\u00a0\u7684\u7ed3\u679c\u3002<\/li>\n<\/ol>\n<\/blockquote>\n<p dir=\"auto\">\u6240\u4ee5\u6bd4\u8f83\u8fc7\u7a0b\u662f\u8fd9\u6837\u7684\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\">\n<pre><span class=\"pl-c1\">1<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">1<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-v\">Number<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">1<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; true<\/span>\r\n<span class=\"pl-c\">\/\/ \u4f46\u662f\u2026\u2026<\/span>\r\n<span class=\"pl-c1\">1.1<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">1.1<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-v\">Number<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\r\n<span class=\"pl-c1\">1.1<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -&gt; false<\/span><\/pre>\n<div class=\"zeroclipboard-container\"><\/div>\n<\/div>\n<ul dir=\"auto\">\n<li><a href=\"https:\/\/262.ecma-international.org\/11.0\/index.html#sec-abstract-equality-comparison\" rel=\"nofollow\"><strong>7.2.15<\/strong>\u00a0\u62bd\u8c61\u76f8\u7b49\u6bd4\u8f83<\/a><\/li>\n<\/ul>\n<h1 id=\"user-content-\u5176\u4ed6\u8d44\u6e90\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#%E5%85%B6%E4%BB%96%E8%B5%84%E6%BA%90\">\u5176\u4ed6\u8d44\u6e90<\/a><\/h1>\n<ul dir=\"auto\">\n<li><a href=\"http:\/\/wtfjs.com\/\" rel=\"nofollow\">wtfjs.com<\/a>\u00a0\u2014 \u4e00\u4e9b\u975e\u5e38\u7279\u522b\u7684\u4e0d\u89c4\u8303\u4e0e\u4e0d\u4e00\u81f4\u7684\u96c6\u5408\uff0c\u4ee5\u53ca\u5bf9\u4e8e web \u7f16\u7a0b\u8bed\u8a00\u6765\u8bf4\u975e\u5e38\u75db\u82e6\u7684\u65f6\u5149\u3002<\/li>\n<li><a href=\"https:\/\/www.destroyallsoftware.com\/talks\/wat\" rel=\"nofollow\">Wat<\/a>\u00a0\u2014 CodeMash 2012 \u4e2d Gary Bernhardt \u7684\u6f14\u8bb2<\/li>\n<li><a href=\"https:\/\/www.youtube.com\/watch?v=2pL28CcEijU\" rel=\"nofollow\">What the&#8230; JavaScript?<\/a>\u00a0\u2014 Kyle Simpsons \u5728 Forward 2 \u7684\u6f14\u8bb2\uff0c\u63cf\u8ff0\u4e86\u201c\u75af\u72c2\u7684 JavaScript\u201d\u3002\u4ed6\u5e0c\u671b\u5e2e\u52a9\u4f60\u5199\u51fa\u66f4\u5e72\u51c0\u3001\u66f4\u4f18\u96c5\u3001\u66f4\u6613\u8bfb\u7684\u4ee3\u7801\uff0c\u9f13\u52b1\u4eba\u4eec\u4e3a\u5f00\u6e90\u793e\u533a\u505a\u51fa\u8d21\u732e\u3002<\/li>\n<li><a href=\"http:\/\/zero.milosz.ca\/\" rel=\"nofollow\">Zeros in JavaScript<\/a>\u00a0\u2014 \u9488\u5bf9 JavaScript \u4e2d\u7684\u00a0<code>==<\/code>\u3001<code>===<\/code>\u3001<code>+<\/code>\u00a0\u548c\u00a0<code>*<\/code>\u00a0\u7684\u771f\u503c\u8868\u3002<\/li>\n<\/ul>\n<h1 id=\"user-content--\u6350\u8d60\u652f\u6301\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E6%8D%90%E8%B5%A0%E6%94%AF%E6%8C%81\">? \u6350\u8d60\u652f\u6301<\/a><\/h1>\n<p dir=\"auto\">\u4f60\u597d\uff01\u8fd9\u4e2a\u9879\u76ee\u662f\u6211\u5728\u7a7a\u95f2\u65f6\u95f4\u505a\u7684\uff0c\u4f5c\u4e3a\u6211\u7684\u4e3b\u8981\u5de5\u4f5c\u7684\u8865\u5145\u3002\u6211\u5e0c\u671b\u4f60\u5728\u9605\u8bfb\u8fd9\u7bc7\u6587\u7ae0\u65f6\u4fdd\u6301\u6109\u5feb\u7684\u5fc3\u60c5\u3002\u8bf7\u8003\u8651\u652f\u6301\u6211 ?\u3002<\/p>\n<p dir=\"auto\">\u6bcf\u4e00\u6b21\u6350\u8d60\u5bf9\u6211\u6765\u8bf4\u610f\u4e49\u91cd\u5927\u3002\u4f60\u7684\u6350\u8d60\u662f\u5bf9\u6211\u7684\u5de5\u4f5c\u7684\u80af\u5b9a\uff1a\u6211\u7684\u5de5\u4f5c\u6709\u4ef7\u503c\u3002<\/p>\n<p dir=\"auto\"><strong>? \u611f\u8c22\u60a8\u7684\u652f\u6301\uff01 ?<\/strong><\/p>\n<table>\n<thead>\n<tr>\n<th>\u670d\u52a1<\/th>\n<th align=\"center\">\u94fe\u63a5<\/th>\n<th align=\"center\">\u52a8\u4f5c<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>Patreon<\/strong><\/td>\n<td align=\"center\"><a href=\"https:\/\/patreon.com\/denysdovhan\" rel=\"nofollow\">Become a patron<\/a><\/td>\n<td align=\"center\"><a href=\"https:\/\/patreon.com\/denysdovhan\" rel=\"nofollow\"><img decoding=\"async\" src=\"https:\/\/camo.githubusercontent.com\/ca317983c1ee436cd8c1157c5d2769c641372ee441af705dc0a32e3654fcbc9f\/68747470733a2f2f63352e70617472656f6e2e636f6d2f65787465726e616c2f6c6f676f2f6265636f6d655f615f706174726f6e5f627574746f6e4032782e706e67\" width=\"120px\" data-canonical-src=\"https:\/\/c5.patreon.com\/external\/logo\/become_a_patron_button@2x.png\" \/><\/a><\/td>\n<\/tr>\n<tr>\n<td><strong>BuyMeACoffee<\/strong><\/td>\n<td align=\"center\"><a href=\"https:\/\/patreon.com\/denysdovhan\" rel=\"nofollow\">Buy me a cup of \u2615\ufe0f or ?<\/a><\/td>\n<td align=\"center\"><a href=\"https:\/\/buymeacoffee.com\/denysdovhan\" rel=\"nofollow\"><img decoding=\"async\" src=\"https:\/\/camo.githubusercontent.com\/7beb1ce9d83217fda4e2ab8c7f975d8eeb4d74122634d14c008e4160aca6b415\/68747470733a2f2f63646e2e6275796d6561636f666665652e636f6d2f627574746f6e732f64656661756c742d626c61636b2e706e67\" width=\"120px\" data-canonical-src=\"https:\/\/cdn.buymeacoffee.com\/buttons\/default-black.png\" \/><\/a><\/td>\n<\/tr>\n<tr>\n<td><strong>Bitcoin<\/strong><\/td>\n<td align=\"center\"><code>1EJsKs6rPsqa7QLoVLpe3wgcdL9Q8WmDxE<\/code><\/td>\n<td align=\"center\"><a href=\"https:\/\/user-images.githubusercontent.com\/3459374\/107130426-0ae4f800-68d6-11eb-9b86-15bf33467615.png\" target=\"_blank\" rel=\"noopener noreferrer nofollow\"><img decoding=\"async\" src=\"https:\/\/user-images.githubusercontent.com\/3459374\/107130426-0ae4f800-68d6-11eb-9b86-15bf33467615.png\" width=\"120px\" \/><\/a><\/td>\n<\/tr>\n<tr>\n<td><strong>Ethereum<\/strong><\/td>\n<td align=\"center\"><code>0x6aF39C917359897ae6969Ad682C14110afe1a0a1<\/code><\/td>\n<td align=\"center\"><a href=\"https:\/\/user-images.githubusercontent.com\/3459374\/107130370-55b24000-68d5-11eb-93f5-075355c7fcd4.png\" target=\"_blank\" rel=\"noopener noreferrer nofollow\"><img decoding=\"async\" src=\"https:\/\/user-images.githubusercontent.com\/3459374\/107130370-55b24000-68d5-11eb-93f5-075355c7fcd4.png\" width=\"120px\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<blockquote>\n<p dir=\"auto\"><strong>\u26a0\ufe0f\u00a0\u63d0\u793a\uff1a<\/strong>\u00a0\u6211\u73b0\u5c45\u4e4c\u514b\u5170\uff0c\u4e4c\u514b\u5170\u7684\u94f6\u884c\u8d26\u6237\u6ca1\u529e\u6cd5\u7ed1\u5b9a PayPal \u6216 Stripe \u4e4b\u7c7b\u7684\u8d26\u6237\u3002\u6240\u4ee5\u6211\u6ca1\u6cd5\u5f00\u542f Github Sponsors\u3001OpenCollective \u548c\u5176\u4ed6\u4f9d\u8d56\u4e8e\u8fd9\u4e9b\u670d\u52a1\u7684\u6350\u8d60\u6e20\u9053\u3002\u5bf9\u4e0d\u8d77\uff0c\u76ee\u524d\u60a8\u53ea\u80fd\u901a\u8fc7\u8fd9\u4e9b\u65b9\u5f0f\u652f\u6301\u6211\u3002<\/p>\n<\/blockquote>\n<h1 id=\"user-content--\u8bb8\u53ef\u8bc1\" dir=\"auto\" tabindex=\"-1\"><a class=\"heading-link\" href=\"https:\/\/github.com\/denysdovhan\/wtfjs\/blob\/master\/README-zh-cn.md#-%E8%AE%B8%E5%8F%AF%E8%AF%81\">? \u8bb8\u53ef\u8bc1<\/a><\/h1>\n<p dir=\"auto\"><a href=\"http:\/\/www.wtfpl.net\/\" rel=\"nofollow\"><img decoding=\"async\" src=\"https:\/\/camo.githubusercontent.com\/8faf26c628ab8cf2a5c40e4673880fd74f525fe5427983bb4c9f99302af8a1a4\/68747470733a2f2f696d672e736869656c64732e696f2f62616467652f4c6963656e73652d575446504c253230322e302d6c69676874677265792e7376673f7374796c653d666c61742d737175617265\" alt=\"CC 4.0\" data-canonical-src=\"https:\/\/img.shields.io\/badge\/License-WTFPL%202.0-lightgrey.svg?style=flat-square\" \/><\/a><\/p>\n<p dir=\"auto\">\u00a9\u00a0<a href=\"http:\/\/denysdovhan.com\/\" rel=\"nofollow\">Denys Dovhan<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>cc from JavaScript \u662f<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"colormag_page_container_layout":"default_layout","colormag_page_sidebar_layout":"default_layout","footnotes":""},"categories":[24],"tags":[121],"class_list":["post-7098","post","type-post","status-publish","format-standard","hentry","category-value_docs","tag-05-"],"_links":{"self":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/7098","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/comments?post=7098"}],"version-history":[{"count":0,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/7098\/revisions"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=7098"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=7098"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=7098"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}