{"id":5772,"date":"2022-05-14T01:23:15","date_gmt":"2022-05-13T17:23:15","guid":{"rendered":"https:\/\/damogame.cn:15443\/wordpress\/?p=5772"},"modified":"2022-05-14T01:23:15","modified_gmt":"2022-05-13T17:23:15","slug":"%e4%ba%86%e4%b8%8d%e8%b5%b7%e7%9a%84-typescript-%e5%85%a5%e9%97%a8%e6%95%99%e7%a8%8b%ef%bc%881-2w%e5%ad%97%ef%bc%89","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/5772","title":{"rendered":"\u4e86\u4e0d\u8d77\u7684 TypeScript \u5165\u95e8\u6559\u7a0b\uff081.2W\u5b57\uff09"},"content":{"rendered":"<header class=\"Post-Header\">\n<div class=\"Post-Author\"><a href=\"https:\/\/zhuanlan.zhihu.com\/p\/147765838\">\u539f\u6587\u5730\u5740<\/a><\/div>\n<div><\/div>\n<div class=\"LabelContainer-wrapper\"><\/div>\n<div tabindex=\"0\" role=\"button\"><span class=\"Voters\"><button class=\"Button Button--plain\" type=\"button\">349 \u4eba\u8d5e\u540c\u4e86\u8be5\u6587\u7ae0<\/button><\/span><\/div>\n<\/header>\n<div class=\"Post-RichTextContainer\">\n<div class=\"css-1yuhvjn\">\n<div class=\"RichText ztext Post-RichText css-14bz7qe\">\n<p data-first-child=\"\" data-pid=\"BnLZEkgo\">\u60f3\u5b66\u4e60 TypeScript \u7684\u5c0f\u4f19\u4f34\u770b\u8fc7\u6765\uff0c\u672c\u6587\u5c06\u5e26\u4f60\u4e00\u6b65\u6b65\u5b66\u4e60 TypeScript \u5165\u95e8\u76f8\u5173\u7684\u5341\u56db\u4e2a\u77e5\u8bc6\u70b9\uff0c\u8be6\u7ec6\u7684\u5185\u5bb9\u5927\u7eb2\u8bf7\u770b\u4e0b\u56fe\uff1a<\/p>\n<figure data-size=\"normal\"><img decoding=\"async\" class=\"origin_image zh-lightbox-thumb lazy\" src=\"https:\/\/pic4.zhimg.com\/80\/v2-53089f6e33eb20b4210f8db8402ce393_1440w.jpg\" width=\"800\" data-caption=\"\" data-size=\"normal\" data-rawwidth=\"800\" data-rawheight=\"675\" data-original=\"https:\/\/pic4.zhimg.com\/v2-53089f6e33eb20b4210f8db8402ce393_r.jpg\" data-actualsrc=\"https:\/\/pic4.zhimg.com\/v2-53089f6e33eb20b4210f8db8402ce393_b.jpg\" data-lazy-status=\"ok\" \/><\/figure>\n<h3>\u4e00\u3001TypeScript \u662f\u4ec0\u4e48<\/h3>\n<p data-pid=\"c6fbS_Jm\"><a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=https%3A\/\/www.typescriptlang.org\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">TypeScript<\/a>\u00a0\u662f\u4e00\u79cd\u7531\u5fae\u8f6f\u5f00\u53d1\u7684\u81ea\u7531\u548c\u5f00\u6e90\u7684\u7f16\u7a0b\u8bed\u8a00\u3002\u5b83\u662f JavaScript \u7684\u4e00\u4e2a\u8d85\u96c6\uff0c\u800c\u4e14\u672c\u8d28\u4e0a\u5411\u8fd9\u4e2a\u8bed\u8a00\u6dfb\u52a0\u4e86\u53ef\u9009\u7684\u9759\u6001\u7c7b\u578b\u548c\u57fa\u4e8e\u7c7b\u7684\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u3002<\/p>\n<p data-pid=\"noTb3tNJ\">TypeScript \u63d0\u4f9b\u6700\u65b0\u7684\u548c\u4e0d\u65ad\u53d1\u5c55\u7684 JavaScript \u7279\u6027\uff0c\u5305\u62ec\u90a3\u4e9b\u6765\u81ea 2015 \u5e74\u7684 ECMAScript \u548c\u672a\u6765\u7684\u63d0\u6848\u4e2d\u7684\u7279\u6027\uff0c\u6bd4\u5982\u5f02\u6b65\u529f\u80fd\u548c Decorators\uff0c\u4ee5\u5e2e\u52a9\u5efa\u7acb\u5065\u58ee\u7684\u7ec4\u4ef6\u3002\u4e0b\u56fe\u663e\u793a\u4e86 TypeScript \u4e0e ES5\u3001ES2015 \u548c ES2016 \u4e4b\u95f4\u7684\u5173\u7cfb\uff1a<\/p>\n<figure data-size=\"normal\"><img decoding=\"async\" class=\"content_image lazy\" src=\"https:\/\/pic4.zhimg.com\/80\/v2-f77bd6c291b3dc9a0e3a9a92c9c2b1bf_1440w.jpg\" width=\"383\" data-caption=\"\" data-size=\"normal\" data-rawwidth=\"383\" data-rawheight=\"383\" data-actualsrc=\"https:\/\/pic4.zhimg.com\/v2-f77bd6c291b3dc9a0e3a9a92c9c2b1bf_b.jpg\" data-lazy-status=\"ok\" \/><\/figure>\n<h3>1.1 TypeScript \u4e0e JavaScript \u7684\u533a\u522b<\/h3>\n<p data-pid=\"grAewTB2\">TypeScriptJavaScriptJavaScript \u7684\u8d85\u96c6\u7528\u4e8e\u89e3\u51b3\u5927\u578b\u9879\u76ee\u7684\u4ee3\u7801\u590d\u6742\u6027\u4e00\u79cd\u811a\u672c\u8bed\u8a00\uff0c\u7528\u4e8e\u521b\u5efa\u52a8\u6001\u7f51\u9875\u3002\u53ef\u4ee5\u5728\u7f16\u8bd1\u671f\u95f4\u53d1\u73b0\u5e76\u7ea0\u6b63\u9519\u8bef\u4f5c\u4e3a\u4e00\u79cd\u89e3\u91ca\u578b\u8bed\u8a00\uff0c\u53ea\u80fd\u5728\u8fd0\u884c\u65f6\u53d1\u73b0\u9519\u8bef\u5f3a\u7c7b\u578b\uff0c\u652f\u6301\u9759\u6001\u548c\u52a8\u6001\u7c7b\u578b\u5f31\u7c7b\u578b\uff0c\u6ca1\u6709\u9759\u6001\u7c7b\u578b\u9009\u9879\u6700\u7ec8\u88ab\u7f16\u8bd1\u6210 JavaScript \u4ee3\u7801\uff0c\u4f7f\u6d4f\u89c8\u5668\u53ef\u4ee5\u7406\u89e3\u53ef\u4ee5\u76f4\u63a5\u5728\u6d4f\u89c8\u5668\u4e2d\u4f7f\u7528\u652f\u6301\u6a21\u5757\u3001\u6cdb\u578b\u548c\u63a5\u53e3\u4e0d\u652f\u6301\u6a21\u5757\uff0c\u6cdb\u578b\u6216\u63a5\u53e3\u652f\u6301 ES3\uff0cES4\uff0cES5 \u548c ES6 \u7b49\u4e0d\u652f\u6301\u7f16\u8bd1\u5176\u4ed6 ES3\uff0cES4\uff0cES5 \u6216 ES6 \u529f\u80fd\u793e\u533a\u7684\u652f\u6301\u4ecd\u5728\u589e\u957f\uff0c\u800c\u4e14\u8fd8\u4e0d\u662f\u5f88\u5927\u5927\u91cf\u7684\u793e\u533a\u652f\u6301\u4ee5\u53ca\u5927\u91cf\u6587\u6863\u548c\u89e3\u51b3\u95ee\u9898\u7684\u652f\u6301<\/p>\n<h3>1.2 \u83b7\u53d6 TypeScript<\/h3>\n<p data-pid=\"6xh4P5Wd\">\u547d\u4ee4\u884c\u7684 TypeScript \u7f16\u8bd1\u5668\u53ef\u4ee5\u4f7f\u7528 Node.js \u5305\u6765\u5b89\u88c5\u3002<\/p>\n<p data-pid=\"3Ei0MVzf\"><b>1.\u5b89\u88c5 TypeScript<\/b><\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">$ npm install -g typescript<\/code><\/pre>\n<\/div>\n<p data-pid=\"sYXXlH3j\"><b>2.\u7f16\u8bd1 TypeScript \u6587\u4ef6<\/b><\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">$ tsc helloworld.ts\r\n# helloworld.ts =&gt; helloworld.js<\/code><\/pre>\n<\/div>\n<p data-pid=\"14T-2ZGj\">\u5f53\u7136\uff0c\u5bf9\u4e8e\u521a\u5165\u95e8 TypeScript \u7684\u5c0f\u4f19\u4f34\uff0c\u4e5f\u53ef\u4ee5\u4e0d\u7528\u5b89\u88c5\u00a0<code>typescript<\/code>\uff0c\u800c\u662f\u76f4\u63a5\u4f7f\u7528\u7ebf\u4e0a\u7684\u00a0<a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=https%3A\/\/www.typescriptlang.org\/play\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">TypeScript Playground<\/a>\u00a0\u6765\u5b66\u4e60\u65b0\u7684\u8bed\u6cd5\u6216\u65b0\u7279\u6027\u3002<\/p>\n<blockquote data-pid=\"CPWVFiNg\"><p>TypeScript Playground\uff1a<a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=https%3A\/\/www.typescriptlang.org\/play\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">https:\/\/www.typescriptlang.or&#8230;<\/a><\/p><\/blockquote>\n<h3>\u4e8c\u3001TypeScript \u57fa\u7840\u7c7b\u578b<\/h3>\n<h3>2.1 Boolean \u7c7b\u578b<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let isDone: boolean = false;\r\n\/\/ ES5\uff1avar isDone = false;<\/code><\/pre>\n<\/div>\n<h3>2.2 Number \u7c7b\u578b<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let count: number = 10;\r\n\/\/ ES5\uff1avar count = 10;<\/code><\/pre>\n<\/div>\n<h3>String \u7c7b\u578b<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let name: string = \"Semliker\";\r\n\/\/ ES5\uff1avar name = 'Semlinker';<\/code><\/pre>\n<\/div>\n<h3>2.4 Array \u7c7b\u578b<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let list: number[] = [1, 2, 3];\r\n\/\/ ES5\uff1avar list = [1,2,3];\r\n\r\nlet list: Array&lt;number&gt; = [1, 2, 3]; \/\/ Array&lt;number&gt;\u6cdb\u578b\u8bed\u6cd5\r\n\/\/ ES5\uff1avar list = [1,2,3];<\/code><\/pre>\n<\/div>\n<h3>2.5 Enum \u7c7b\u578b<\/h3>\n<p data-pid=\"NSoYg2NI\">\u4f7f\u7528\u679a\u4e3e\u6211\u4eec\u53ef\u4ee5\u5b9a\u4e49\u4e00\u4e9b\u5e26\u540d\u5b57\u7684\u5e38\u91cf\u3002 \u4f7f\u7528\u679a\u4e3e\u53ef\u4ee5\u6e05\u6670\u5730\u8868\u8fbe\u610f\u56fe\u6216\u521b\u5efa\u4e00\u7ec4\u6709\u533a\u522b\u7684\u7528\u4f8b\u3002 TypeScript \u652f\u6301\u6570\u5b57\u7684\u548c\u57fa\u4e8e\u5b57\u7b26\u4e32\u7684\u679a\u4e3e\u3002<\/p>\n<p data-pid=\"fsiAPxPh\"><b>1.\u6570\u5b57\u679a\u4e3e<\/b><\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">enum Direction {\r\n  NORTH,\r\n  SOUTH,\r\n  EAST,\r\n  WEST,\r\n}\r\n\r\nlet dir: Direction = Direction.NORTH;<\/code><\/pre>\n<\/div>\n<p data-pid=\"5Wi3W7u9\">\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0cNORTH \u7684\u521d\u59cb\u503c\u4e3a 0\uff0c\u5176\u4f59\u7684\u6210\u5458\u4f1a\u4ece 1 \u5f00\u59cb\u81ea\u52a8\u589e\u957f\u3002\u6362\u53e5\u8bdd\u8bf4\uff0cDirection.SOUTH \u7684\u503c\u4e3a 1\uff0cDirection.EAST \u7684\u503c\u4e3a 2\uff0cDirection.WEST \u7684\u503c\u4e3a 3\u3002\u4e0a\u9762\u7684\u679a\u4e3e\u793a\u4f8b\u4ee3\u7801\u7ecf\u8fc7\u7f16\u8bd1\u540e\u4f1a\u751f\u6210\u4ee5\u4e0b\u4ee3\u7801\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-js\"><span class=\"s2\">\"use strict\"<\/span><span class=\"p\">;<\/span>\r\n<span class=\"kd\">var<\/span> <span class=\"nx\">Direction<\/span><span class=\"p\">;<\/span>\r\n<span class=\"p\">(<\/span><span class=\"kd\">function<\/span> <span class=\"p\">(<\/span><span class=\"nx\">Direction<\/span><span class=\"p\">)<\/span> <span class=\"p\">{<\/span>\r\n  <span class=\"nx\">Direction<\/span><span class=\"p\">[(<\/span><span class=\"nx\">Direction<\/span><span class=\"p\">[<\/span><span class=\"s2\">\"NORTH\"<\/span><span class=\"p\">]<\/span> <span class=\"o\">=<\/span> <span class=\"mi\">0<\/span><span class=\"p\">)]<\/span> <span class=\"o\">=<\/span> <span class=\"s2\">\"NORTH\"<\/span><span class=\"p\">;<\/span>\r\n  <span class=\"nx\">Direction<\/span><span class=\"p\">[(<\/span><span class=\"nx\">Direction<\/span><span class=\"p\">[<\/span><span class=\"s2\">\"SOUTH\"<\/span><span class=\"p\">]<\/span> <span class=\"o\">=<\/span> <span class=\"mi\">1<\/span><span class=\"p\">)]<\/span> <span class=\"o\">=<\/span> <span class=\"s2\">\"SOUTH\"<\/span><span class=\"p\">;<\/span>\r\n  <span class=\"nx\">Direction<\/span><span class=\"p\">[(<\/span><span class=\"nx\">Direction<\/span><span class=\"p\">[<\/span><span class=\"s2\">\"EAST\"<\/span><span class=\"p\">]<\/span> <span class=\"o\">=<\/span> <span class=\"mi\">2<\/span><span class=\"p\">)]<\/span> <span class=\"o\">=<\/span> <span class=\"s2\">\"EAST\"<\/span><span class=\"p\">;<\/span>\r\n  <span class=\"nx\">Direction<\/span><span class=\"p\">[(<\/span><span class=\"nx\">Direction<\/span><span class=\"p\">[<\/span><span class=\"s2\">\"WEST\"<\/span><span class=\"p\">]<\/span> <span class=\"o\">=<\/span> <span class=\"mi\">3<\/span><span class=\"p\">)]<\/span> <span class=\"o\">=<\/span> <span class=\"s2\">\"WEST\"<\/span><span class=\"p\">;<\/span>\r\n<span class=\"p\">})(<\/span><span class=\"nx\">Direction<\/span> <span class=\"o\">||<\/span> <span class=\"p\">(<\/span><span class=\"nx\">Direction<\/span> <span class=\"o\">=<\/span> <span class=\"p\">{}));<\/span>\r\n<span class=\"kd\">var<\/span> <span class=\"nx\">dir<\/span> <span class=\"o\">=<\/span> <span class=\"nx\">Direction<\/span><span class=\"p\">.<\/span><span class=\"nx\">NORTH<\/span><span class=\"p\">;<\/span>\r\n<\/code><\/pre>\n<\/div>\n<p data-pid=\"lzvGGQWr\">\u5f53\u7136\u6211\u4eec\u4e5f\u53ef\u4ee5\u8bbe\u7f6e NORTH \u7684\u521d\u59cb\u503c\uff0c\u6bd4\u5982\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">enum Direction {\r\n  NORTH = 3,\r\n  SOUTH,\r\n  EAST,\r\n  WEST,\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"vBSNd-ew\"><b>2.\u5b57\u7b26\u4e32\u679a\u4e3e<\/b><\/p>\n<p data-pid=\"rKYwrihz\">\u5728 TypeScript 2.4 \u7248\u672c\uff0c\u5141\u8bb8\u6211\u4eec\u4f7f\u7528\u5b57\u7b26\u4e32\u679a\u4e3e\u3002\u5728\u4e00\u4e2a\u5b57\u7b26\u4e32\u679a\u4e3e\u91cc\uff0c\u6bcf\u4e2a\u6210\u5458\u90fd\u5fc5\u987b\u7528\u5b57\u7b26\u4e32\u5b57\u9762\u91cf\uff0c\u6216\u53e6\u5916\u4e00\u4e2a\u5b57\u7b26\u4e32\u679a\u4e3e\u6210\u5458\u8fdb\u884c\u521d\u59cb\u5316\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">enum Direction {\r\n  NORTH = \"NORTH\",\r\n  SOUTH = \"SOUTH\",\r\n  EAST = \"EAST\",\r\n  WEST = \"WEST\",\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"5nNGctKl\">\u4ee5\u4e0a\u4ee3\u7801\u5bf9\u4e8e\u7684 ES5 \u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">\"use strict\";\r\nvar Direction;\r\n(function (Direction) {\r\n    Direction[\"NORTH\"] = \"NORTH\";\r\n    Direction[\"SOUTH\"] = \"SOUTH\";\r\n    Direction[\"EAST\"] = \"EAST\";\r\n    Direction[\"WEST\"] = \"WEST\";\r\n})(Direction || (Direction = {}));<\/code><\/pre>\n<\/div>\n<p data-pid=\"B7c2CQTY\"><b>3.\u5f02\u6784\u679a\u4e3e<\/b><\/p>\n<p data-pid=\"QFXvDgIJ\">\u5f02\u6784\u679a\u4e3e\u7684\u6210\u5458\u503c\u662f\u6570\u5b57\u548c\u5b57\u7b26\u4e32\u7684\u6df7\u5408\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">enum Enum {\r\n  A,\r\n  B,\r\n  C = \"C\",\r\n  D = \"D\",\r\n  E = 8,\r\n  F,\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"hYqp0XA8\">\u4ee5\u4e0a\u4ee3\u7801\u5bf9\u4e8e\u7684 ES5 \u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">\"use strict\";\r\nvar Enum;\r\n(function (Enum) {\r\n    Enum[Enum[\"A\"] = 0] = \"A\";\r\n    Enum[Enum[\"B\"] = 1] = \"B\";\r\n    Enum[\"C\"] = \"C\";\r\n    Enum[\"D\"] = \"D\";\r\n    Enum[Enum[\"E\"] = 8] = \"E\";\r\n    Enum[Enum[\"F\"] = 9] = \"F\";\r\n})(Enum || (Enum = {}));<\/code><\/pre>\n<\/div>\n<p data-pid=\"oYL0hVJV\">\u901a\u8fc7\u89c2\u5bdf\u4e0a\u8ff0\u751f\u6210\u7684 ES5 \u4ee3\u7801\uff0c\u6211\u4eec\u53ef\u4ee5\u53d1\u73b0\u6570\u5b57\u679a\u4e3e\u76f8\u5bf9\u5b57\u7b26\u4e32\u679a\u4e3e\u591a\u4e86 \u201c\u53cd\u5411\u6620\u5c04\u201d\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-js\"><span class=\"nx\">console<\/span><span class=\"p\">.<\/span><span class=\"nx\">log<\/span><span class=\"p\">(<\/span><span class=\"nx\">Enum<\/span><span class=\"p\">.<\/span><span class=\"nx\">A<\/span><span class=\"p\">)<\/span> <span class=\"c1\">\/\/\u8f93\u51fa\uff1a0\r\n<\/span><span class=\"nx\">console<\/span><span class=\"p\">.<\/span><span class=\"nx\">log<\/span><span class=\"p\">(<\/span><span class=\"nx\">Enum<\/span><span class=\"p\">[<\/span><span class=\"mi\">0<\/span><span class=\"p\">])<\/span> <span class=\"c1\">\/\/ \u8f93\u51fa\uff1aA\r\n<\/span><\/code><\/pre>\n<\/div>\n<h3>2.6 Any \u7c7b\u578b<\/h3>\n<p data-pid=\"Gpm89g0z\">\u5728 TypeScript \u4e2d\uff0c\u4efb\u4f55\u7c7b\u578b\u90fd\u53ef\u4ee5\u88ab\u5f52\u4e3a any \u7c7b\u578b\u3002\u8fd9\u8ba9 any \u7c7b\u578b\u6210\u4e3a\u4e86\u7c7b\u578b\u7cfb\u7edf\u7684\u9876\u7ea7\u7c7b\u578b\uff08\u4e5f\u88ab\u79f0\u4f5c\u5168\u5c40\u8d85\u7ea7\u7c7b\u578b\uff09\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let notSure: any = 666;\r\nnotSure = \"Semlinker\";\r\nnotSure = false;<\/code><\/pre>\n<\/div>\n<p data-pid=\"ORYk1pDx\"><code>any<\/code>\u00a0\u7c7b\u578b\u672c\u8d28\u4e0a\u662f\u7c7b\u578b\u7cfb\u7edf\u7684\u4e00\u4e2a\u9003\u9038\u8231\u3002\u4f5c\u4e3a\u5f00\u53d1\u8005\uff0c\u8fd9\u7ed9\u4e86\u6211\u4eec\u5f88\u5927\u7684\u81ea\u7531\uff1aTypeScript \u5141\u8bb8\u6211\u4eec\u5bf9\u00a0<code>any<\/code>\u00a0\u7c7b\u578b\u7684\u503c\u6267\u884c\u4efb\u4f55\u64cd\u4f5c\uff0c\u800c\u65e0\u9700\u4e8b\u5148\u6267\u884c\u4efb\u4f55\u5f62\u5f0f\u7684\u68c0\u67e5\u3002\u6bd4\u5982\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let value: any;\r\n\r\nvalue.foo.bar; \/\/ OK\r\nvalue.trim(); \/\/ OK\r\nvalue(); \/\/ OK\r\nnew value(); \/\/ OK\r\nvalue[0][1]; \/\/ OK<\/code><\/pre>\n<\/div>\n<p data-pid=\"VymuBr5x\">\u5728\u8bb8\u591a\u573a\u666f\u4e0b\uff0c\u8fd9\u592a\u5bbd\u677e\u4e86\u3002\u4f7f\u7528\u00a0<code>any<\/code>\u00a0\u7c7b\u578b\uff0c\u53ef\u4ee5\u5f88\u5bb9\u6613\u5730\u7f16\u5199\u7c7b\u578b\u6b63\u786e\u4f46\u5728\u8fd0\u884c\u65f6\u6709\u95ee\u9898\u7684\u4ee3\u7801\u3002\u5982\u679c\u6211\u4eec\u4f7f\u7528\u00a0<code>any<\/code>\u00a0\u7c7b\u578b\uff0c\u5c31\u65e0\u6cd5\u4f7f\u7528 TypeScript \u63d0\u4f9b\u7684\u5927\u91cf\u7684\u4fdd\u62a4\u673a\u5236\u3002\u4e3a\u4e86\u89e3\u51b3\u00a0<code>any<\/code>\u00a0\u5e26\u6765\u7684\u95ee\u9898\uff0cTypeScript 3.0 \u5f15\u5165\u4e86\u00a0<code>unknown<\/code>\u00a0\u7c7b\u578b\u3002<\/p>\n<h3>2.7 Unknown \u7c7b\u578b<\/h3>\n<p data-pid=\"ABzk1oBD\">\u5c31\u50cf\u6240\u6709\u7c7b\u578b\u90fd\u53ef\u4ee5\u8d4b\u503c\u7ed9\u00a0<code>any<\/code>\uff0c\u6240\u6709\u7c7b\u578b\u4e5f\u90fd\u53ef\u4ee5\u8d4b\u503c\u7ed9\u00a0<code>unknown<\/code>\u3002\u8fd9\u4f7f\u5f97\u00a0<code>unknown<\/code>\u00a0\u6210\u4e3a TypeScript \u7c7b\u578b\u7cfb\u7edf\u7684\u53e6\u4e00\u79cd\u9876\u7ea7\u7c7b\u578b\uff08\u53e6\u4e00\u79cd\u662f\u00a0<code>any<\/code>\uff09\u3002\u4e0b\u9762\u6211\u4eec\u6765\u770b\u4e00\u4e0b\u00a0<code>unknown<\/code>\u00a0\u7c7b\u578b\u7684\u4f7f\u7528\u793a\u4f8b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let value: unknown;\r\n\r\nvalue = true; \/\/ OK\r\nvalue = 42; \/\/ OK\r\nvalue = \"Hello World\"; \/\/ OK\r\nvalue = []; \/\/ OK\r\nvalue = {}; \/\/ OK\r\nvalue = Math.random; \/\/ OK\r\nvalue = null; \/\/ OK\r\nvalue = undefined; \/\/ OK\r\nvalue = new TypeError(); \/\/ OK\r\nvalue = Symbol(\"type\"); \/\/ OK<\/code><\/pre>\n<\/div>\n<p data-pid=\"kP0CVD9L\">\u5bf9\u00a0<code>value<\/code>\u00a0\u53d8\u91cf\u7684\u6240\u6709\u8d4b\u503c\u90fd\u88ab\u8ba4\u4e3a\u662f\u7c7b\u578b\u6b63\u786e\u7684\u3002\u4f46\u662f\uff0c\u5f53\u6211\u4eec\u5c1d\u8bd5\u5c06\u7c7b\u578b\u4e3a\u00a0<code>unknown<\/code>\u00a0\u7684\u503c\u8d4b\u503c\u7ed9\u5176\u4ed6\u7c7b\u578b\u7684\u53d8\u91cf\u65f6\u4f1a\u53d1\u751f\u4ec0\u4e48\uff1f<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let value: unknown;\r\n\r\nlet value1: unknown = value; \/\/ OK\r\nlet value2: any = value; \/\/ OK\r\nlet value3: boolean = value; \/\/ Error\r\nlet value4: number = value; \/\/ Error\r\nlet value5: string = value; \/\/ Error\r\nlet value6: object = value; \/\/ Error\r\nlet value7: any[] = value; \/\/ Error\r\nlet value8: Function = value; \/\/ Error<\/code><\/pre>\n<\/div>\n<p data-pid=\"7cp07iNV\"><code>unknown<\/code>\u00a0\u7c7b\u578b\u53ea\u80fd\u88ab\u8d4b\u503c\u7ed9\u00a0<code>any<\/code>\u00a0\u7c7b\u578b\u548c\u00a0<code>unknown<\/code>\u00a0\u7c7b\u578b\u672c\u8eab\u3002\u76f4\u89c2\u5730\u8bf4\uff0c\u8fd9\u662f\u6709\u9053\u7406\u7684\uff1a\u53ea\u6709\u80fd\u591f\u4fdd\u5b58\u4efb\u610f\u7c7b\u578b\u503c\u7684\u5bb9\u5668\u624d\u80fd\u4fdd\u5b58\u00a0<code>unknown<\/code>\u00a0\u7c7b\u578b\u7684\u503c\u3002\u6bd5\u7adf\u6211\u4eec\u4e0d\u77e5\u9053\u53d8\u91cf\u00a0<code>value<\/code>\u00a0\u4e2d\u5b58\u50a8\u4e86\u4ec0\u4e48\u7c7b\u578b\u7684\u503c\u3002<\/p>\n<p data-pid=\"DeTAeVFk\">\u73b0\u5728\u8ba9\u6211\u4eec\u770b\u770b\u5f53\u6211\u4eec\u5c1d\u8bd5\u5bf9\u7c7b\u578b\u4e3a\u00a0<code>unknown<\/code>\u00a0\u7684\u503c\u6267\u884c\u64cd\u4f5c\u65f6\u4f1a\u53d1\u751f\u4ec0\u4e48\u3002\u4ee5\u4e0b\u662f\u6211\u4eec\u5728\u4e4b\u524d\u00a0<code>any<\/code>\u00a0\u7ae0\u8282\u770b\u8fc7\u7684\u76f8\u540c\u64cd\u4f5c\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let value: unknown;\r\n\r\nvalue.foo.bar; \/\/ Error\r\nvalue.trim(); \/\/ Error\r\nvalue(); \/\/ Error\r\nnew value(); \/\/ Error\r\nvalue[0][1]; \/\/ Error<\/code><\/pre>\n<\/div>\n<p data-pid=\"Tzny5JGV\">\u5c06\u00a0<code>value<\/code>\u00a0\u53d8\u91cf\u7c7b\u578b\u8bbe\u7f6e\u4e3a\u00a0<code>unknown<\/code>\u00a0\u540e\uff0c\u8fd9\u4e9b\u64cd\u4f5c\u90fd\u4e0d\u518d\u88ab\u8ba4\u4e3a\u662f\u7c7b\u578b\u6b63\u786e\u7684\u3002\u901a\u8fc7\u5c06\u00a0<code>any<\/code>\u00a0\u7c7b\u578b\u6539\u53d8\u4e3a\u00a0<code>unknown<\/code>\u00a0\u7c7b\u578b\uff0c\u6211\u4eec\u5df2\u5c06\u5141\u8bb8\u6240\u6709\u66f4\u6539\u7684\u9ed8\u8ba4\u8bbe\u7f6e\uff0c\u66f4\u6539\u4e3a\u7981\u6b62\u4efb\u4f55\u66f4\u6539\u3002<\/p>\n<h3>2.8 Tuple \u7c7b\u578b<\/h3>\n<p data-pid=\"Qd53YQO3\">\u4f17\u6240\u5468\u77e5\uff0c\u6570\u7ec4\u4e00\u822c\u7531\u540c\u79cd\u7c7b\u578b\u7684\u503c\u7ec4\u6210\uff0c\u4f46\u6709\u65f6\u6211\u4eec\u9700\u8981\u5728\u5355\u4e2a\u53d8\u91cf\u4e2d\u5b58\u50a8\u4e0d\u540c\u7c7b\u578b\u7684\u503c\uff0c\u8fd9\u65f6\u5019\u6211\u4eec\u5c31\u53ef\u4ee5\u4f7f\u7528\u5143\u7ec4\u3002\u5728 JavaScript \u4e2d\u662f\u6ca1\u6709\u5143\u7ec4\u7684\uff0c\u5143\u7ec4\u662f TypeScript \u4e2d\u7279\u6709\u7684\u7c7b\u578b\uff0c\u5176\u5de5\u4f5c\u65b9\u5f0f\u7c7b\u4f3c\u4e8e\u6570\u7ec4\u3002<\/p>\n<p data-pid=\"rzQlxVl1\">\u5143\u7ec4\u53ef\u7528\u4e8e\u5b9a\u4e49\u5177\u6709\u6709\u9650\u6570\u91cf\u7684\u672a\u547d\u540d\u5c5e\u6027\u7684\u7c7b\u578b\u3002\u6bcf\u4e2a\u5c5e\u6027\u90fd\u6709\u4e00\u4e2a\u5173\u8054\u7684\u7c7b\u578b\u3002\u4f7f\u7528\u5143\u7ec4\u65f6\uff0c\u5fc5\u987b\u63d0\u4f9b\u6bcf\u4e2a\u5c5e\u6027\u7684\u503c\u3002\u4e3a\u4e86\u66f4\u76f4\u89c2\u5730\u7406\u89e3\u5143\u7ec4\u7684\u6982\u5ff5\uff0c\u6211\u4eec\u6765\u770b\u4e00\u4e2a\u5177\u4f53\u7684\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let tupleType: [string, boolean];\r\ntupleType = [\"Semlinker\", true];<\/code><\/pre>\n<\/div>\n<p data-pid=\"Sh71cM-Z\">\u5728\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u6211\u4eec\u5b9a\u4e49\u4e86\u4e00\u4e2a\u540d\u4e3a\u00a0<code>tupleType<\/code>\u00a0\u7684\u53d8\u91cf\uff0c\u5b83\u7684\u7c7b\u578b\u662f\u4e00\u4e2a\u7c7b\u578b\u6570\u7ec4\u00a0<code>[string, boolean]<\/code>\uff0c\u7136\u540e\u6211\u4eec\u6309\u7167\u6b63\u786e\u7684\u7c7b\u578b\u4f9d\u6b21\u521d\u59cb\u5316 tupleType \u53d8\u91cf\u3002\u4e0e\u6570\u7ec4\u4e00\u6837\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u4e0b\u6807\u6765\u8bbf\u95ee\u5143\u7ec4\u4e2d\u7684\u5143\u7d20\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">console.log(tupleType[0]); \/\/ Semlinker\r\nconsole.log(tupleType[1]); \/\/ true<\/code><\/pre>\n<\/div>\n<p data-pid=\"gc8zT3Wi\">\u5728\u5143\u7ec4\u521d\u59cb\u5316\u7684\u65f6\u5019\uff0c\u5982\u679c\u51fa\u73b0\u7c7b\u578b\u4e0d\u5339\u914d\u7684\u8bdd\uff0c\u6bd4\u5982\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">tupleType = [true, \"Semlinker\"];<\/code><\/pre>\n<\/div>\n<p data-pid=\"ihxYvjcd\">\u6b64\u65f6\uff0cTypeScript \u7f16\u8bd1\u5668\u4f1a\u63d0\u793a\u4ee5\u4e0b\u9519\u8bef\u4fe1\u606f\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">[0]: Type 'true' is not assignable to type 'string'.\r\n[1]: Type 'string' is not assignable to type 'boolean'.<\/code><\/pre>\n<\/div>\n<p data-pid=\"sNbb5RVW\">\u5f88\u660e\u663e\u662f\u56e0\u4e3a\u7c7b\u578b\u4e0d\u5339\u914d\u5bfc\u81f4\u7684\u3002\u5728\u5143\u7ec4\u521d\u59cb\u5316\u7684\u65f6\u5019\uff0c\u6211\u4eec\u8fd8\u5fc5\u987b\u63d0\u4f9b\u6bcf\u4e2a\u5c5e\u6027\u7684\u503c\uff0c\u4e0d\u7136\u4e5f\u4f1a\u51fa\u73b0\u9519\u8bef\uff0c\u6bd4\u5982\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">tupleType = [\"Semlinker\"];<\/code><\/pre>\n<\/div>\n<p data-pid=\"1QwkfkKe\">\u6b64\u65f6\uff0cTypeScript \u7f16\u8bd1\u5668\u4f1a\u63d0\u793a\u4ee5\u4e0b\u9519\u8bef\u4fe1\u606f\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">Property '1' is missing in type '[string]' but required in type '[string, boolean]'.<\/code><\/pre>\n<\/div>\n<h3>2.9 Void \u7c7b\u578b<\/h3>\n<p data-pid=\"o_YrVlqf\">\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u6765\u8bf4\uff0cvoid \u7c7b\u578b\u50cf\u662f\u4e0e any \u7c7b\u578b\u76f8\u53cd\uff0c\u5b83\u8868\u793a\u6ca1\u6709\u4efb\u4f55\u7c7b\u578b\u3002\u5f53\u4e00\u4e2a\u51fd\u6570\u6ca1\u6709\u8fd4\u56de\u503c\u65f6\uff0c\u4f60\u901a\u5e38\u4f1a\u89c1\u5230\u5176\u8fd4\u56de\u503c\u7c7b\u578b\u662f void\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">\/\/ \u58f0\u660e\u51fd\u6570\u8fd4\u56de\u503c\u4e3avoid\r\nfunction warnUser(): void {\r\n  console.log(\"This is my warning message\");\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"-4MxHEkm\">\u4ee5\u4e0a\u4ee3\u7801\u7f16\u8bd1\u751f\u6210\u7684 ES5 \u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">\"use strict\";\r\nfunction warnUser() {\r\n  console.log(\"This is my warning message\");\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"_7dQDiRw\">\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u58f0\u660e\u4e00\u4e2a void \u7c7b\u578b\u7684\u53d8\u91cf\u6ca1\u6709\u4ec0\u4e48\u4f5c\u7528\uff0c\u56e0\u4e3a\u5b83\u7684\u503c\u53ea\u80fd\u4e3a\u00a0<code>undefined<\/code>\u00a0\u6216\u00a0<code>null<\/code>\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let unusable: void = undefined;<\/code><\/pre>\n<\/div>\n<h3>2.10 Null \u548c Undefined \u7c7b\u578b<\/h3>\n<p data-pid=\"ny8XAC8w\">TypeScript \u91cc\uff0c<code>undefined<\/code>\u00a0\u548c\u00a0<code>null<\/code>\u00a0\u4e24\u8005\u6709\u5404\u81ea\u7684\u7c7b\u578b\u5206\u522b\u4e3a\u00a0<code>undefined<\/code>\u00a0\u548c\u00a0<code>null<\/code>\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let u: undefined = undefined;\r\nlet n: null = null;<\/code><\/pre>\n<\/div>\n<p data-pid=\"fzOfSIz6\">\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u00a0<code>null<\/code>\u00a0\u548c\u00a0<code>undefined<\/code>\u00a0\u662f\u6240\u6709\u7c7b\u578b\u7684\u5b50\u7c7b\u578b\u3002 \u5c31\u662f\u8bf4\u4f60\u53ef\u4ee5\u628a\u00a0<code>null<\/code>\u00a0\u548c\u00a0<code>undefined<\/code>\u00a0\u8d4b\u503c\u7ed9\u00a0<code>number<\/code>\u7c7b\u578b\u7684\u53d8\u91cf\u3002<b>\u7136\u800c\uff0c\u5982\u679c\u4f60\u6307\u5b9a\u4e86<code>--strictNullChecks<\/code><\/b>\u00a0<b>\u6807\u8bb0\uff0c<code>null<\/code><\/b>\u00a0<b>\u548c<\/b>\u00a0<code><b>undefined<\/b><\/code>\u00a0<b>\u53ea\u80fd\u8d4b\u503c\u7ed9<\/b>\u00a0<code><b>void<\/b><\/code>\u00a0<b>\u548c\u5b83\u4eec\u5404\u81ea\u7684\u7c7b\u578b\u3002<\/b><\/p>\n<h3>2.11 Never \u7c7b\u578b<\/h3>\n<p data-pid=\"mEx5GwMV\"><code>never<\/code>\u00a0\u7c7b\u578b\u8868\u793a\u7684\u662f\u90a3\u4e9b\u6c38\u4e0d\u5b58\u5728\u7684\u503c\u7684\u7c7b\u578b\u3002 \u4f8b\u5982\uff0c<code>never<\/code>\u00a0\u7c7b\u578b\u662f\u90a3\u4e9b\u603b\u662f\u4f1a\u629b\u51fa\u5f02\u5e38\u6216\u6839\u672c\u5c31\u4e0d\u4f1a\u6709\u8fd4\u56de\u503c\u7684\u51fd\u6570\u8868\u8fbe\u5f0f\u6216\u7bad\u5934\u51fd\u6570\u8868\u8fbe\u5f0f\u7684\u8fd4\u56de\u503c\u7c7b\u578b\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">\/\/ \u8fd4\u56denever\u7684\u51fd\u6570\u5fc5\u987b\u5b58\u5728\u65e0\u6cd5\u8fbe\u5230\u7684\u7ec8\u70b9\r\nfunction error(message: string): never {\r\n  throw new Error(message);\r\n}\r\n\r\nfunction infiniteLoop(): never {\r\n  while (true) {}\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"q09UjrGj\">\u5728 TypeScript \u4e2d\uff0c\u53ef\u4ee5\u5229\u7528 never \u7c7b\u578b\u7684\u7279\u6027\u6765\u5b9e\u73b0\u5168\u9762\u6027\u68c0\u67e5\uff0c\u5177\u4f53\u793a\u4f8b\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">type Foo = string | number;\r\n\r\nfunction controlFlowAnalysisWithNever(foo: Foo) {\r\n  if (typeof foo === \"string\") {\r\n    \/\/ \u8fd9\u91cc foo \u88ab\u6536\u7a84\u4e3a string \u7c7b\u578b\r\n  } else if (typeof foo === \"number\") {\r\n    \/\/ \u8fd9\u91cc foo \u88ab\u6536\u7a84\u4e3a number \u7c7b\u578b\r\n  } else {\r\n    \/\/ foo \u5728\u8fd9\u91cc\u662f never\r\n    const check: never = foo;\r\n  }\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"y-AVGjro\">\u6ce8\u610f\u5728 else \u5206\u652f\u91cc\u9762\uff0c\u6211\u4eec\u628a\u6536\u7a84\u4e3a never \u7684 foo \u8d4b\u503c\u7ed9\u4e00\u4e2a\u663e\u793a\u58f0\u660e\u7684 never \u53d8\u91cf\u3002\u5982\u679c\u4e00\u5207\u903b\u8f91\u6b63\u786e\uff0c\u90a3\u4e48\u8fd9\u91cc\u5e94\u8be5\u80fd\u591f\u7f16\u8bd1\u901a\u8fc7\u3002\u4f46\u662f\u5047\u5982\u540e\u6765\u6709\u4e00\u5929\u4f60\u7684\u540c\u4e8b\u4fee\u6539\u4e86 Foo \u7684\u7c7b\u578b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">type Foo = string | number | boolean;<\/code><\/pre>\n<\/div>\n<p data-pid=\"ch2zOTxo\">\u7136\u800c\u4ed6\u5fd8\u8bb0\u540c\u65f6\u4fee\u6539\u00a0<code>controlFlowAnalysisWithNever<\/code>\u00a0\u65b9\u6cd5\u4e2d\u7684\u63a7\u5236\u6d41\u7a0b\uff0c\u8fd9\u65f6\u5019 else \u5206\u652f\u7684 foo \u7c7b\u578b\u4f1a\u88ab\u6536\u7a84\u4e3a\u00a0<code>boolean<\/code>\u00a0\u7c7b\u578b\uff0c\u5bfc\u81f4\u65e0\u6cd5\u8d4b\u503c\u7ed9 never \u7c7b\u578b\uff0c\u8fd9\u65f6\u5c31\u4f1a\u4ea7\u751f\u4e00\u4e2a\u7f16\u8bd1\u9519\u8bef\u3002\u901a\u8fc7\u8fd9\u4e2a\u65b9\u5f0f\uff0c\u6211\u4eec\u53ef\u4ee5\u786e\u4fdd<\/p>\n<p data-pid=\"Cxr2M46W\"><code>controlFlowAnalysisWithNever<\/code>\u00a0\u65b9\u6cd5\u603b\u662f\u7a77\u5c3d\u4e86 Foo \u7684\u6240\u6709\u53ef\u80fd\u7c7b\u578b\u3002 \u901a\u8fc7\u8fd9\u4e2a\u793a\u4f8b\uff0c\u6211\u4eec\u53ef\u4ee5\u5f97\u51fa\u4e00\u4e2a\u7ed3\u8bba\uff1a<b>\u4f7f\u7528 never \u907f\u514d\u51fa\u73b0\u65b0\u589e\u4e86\u8054\u5408\u7c7b\u578b\u6ca1\u6709\u5bf9\u5e94\u7684\u5b9e\u73b0\uff0c\u76ee\u7684\u5c31\u662f\u5199\u51fa\u7c7b\u578b\u7edd\u5bf9\u5b89\u5168\u7684\u4ee3\u7801\u3002<\/b><\/p>\n<h3>\u4e09\u3001TypeScript \u65ad\u8a00<\/h3>\n<p data-pid=\"fXeDMqrC\">\u6709\u65f6\u5019\u4f60\u4f1a\u9047\u5230\u8fd9\u6837\u7684\u60c5\u51b5\uff0c\u4f60\u4f1a\u6bd4 TypeScript \u66f4\u4e86\u89e3\u67d0\u4e2a\u503c\u7684\u8be6\u7ec6\u4fe1\u606f\u3002\u901a\u5e38\u8fd9\u4f1a\u53d1\u751f\u5728\u4f60\u6e05\u695a\u5730\u77e5\u9053\u4e00\u4e2a\u5b9e\u4f53\u5177\u6709\u6bd4\u5b83\u73b0\u6709\u7c7b\u578b\u66f4\u786e\u5207\u7684\u7c7b\u578b\u3002<\/p>\n<p data-pid=\"2fosUYq-\">\u901a\u8fc7\u7c7b\u578b\u65ad\u8a00\u8fd9\u79cd\u65b9\u5f0f\u53ef\u4ee5\u544a\u8bc9\u7f16\u8bd1\u5668\uff0c\u201c\u76f8\u4fe1\u6211\uff0c\u6211\u77e5\u9053\u81ea\u5df1\u5728\u5e72\u4ec0\u4e48\u201d\u3002\u7c7b\u578b\u65ad\u8a00\u597d\u6bd4\u5176\u4ed6\u8bed\u8a00\u91cc\u7684\u7c7b\u578b\u8f6c\u6362\uff0c\u4f46\u662f\u4e0d\u8fdb\u884c\u7279\u6b8a\u7684\u6570\u636e\u68c0\u67e5\u548c\u89e3\u6784\u3002\u5b83\u6ca1\u6709\u8fd0\u884c\u65f6\u7684\u5f71\u54cd\uff0c\u53ea\u662f\u5728\u7f16\u8bd1\u9636\u6bb5\u8d77\u4f5c\u7528\u3002<\/p>\n<p data-pid=\"54oZEwzA\">\u7c7b\u578b\u65ad\u8a00\u6709\u4e24\u79cd\u5f62\u5f0f\uff1a<\/p>\n<h3>3.1 \u201c\u5c16\u62ec\u53f7\u201d \u8bed\u6cd5<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let someValue: any = \"this is a string\";\r\nlet strLength: number = (&lt;string&gt;someValue).length;<\/code><\/pre>\n<\/div>\n<h3>3.2 as \u8bed\u6cd5<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let someValue: any = \"this is a string\";\r\nlet strLength: number = (someValue as string).length;<\/code><\/pre>\n<\/div>\n<h3>\u56db\u3001\u7c7b\u578b\u5b88\u536b<\/h3>\n<blockquote data-pid=\"tFtxib64\"><p>A type guard is some expression that performs a runtime check that guarantees the type in some scope. \u2014\u2014 TypeScript \u5b98\u65b9\u6587\u6863<\/p><\/blockquote>\n<p data-pid=\"V_3zpfrQ\">\u7c7b\u578b\u4fdd\u62a4\u662f\u53ef\u6267\u884c\u8fd0\u884c\u65f6\u68c0\u67e5\u7684\u4e00\u79cd\u8868\u8fbe\u5f0f\uff0c\u7528\u4e8e\u786e\u4fdd\u8be5\u7c7b\u578b\u5728\u4e00\u5b9a\u7684\u8303\u56f4\u5185\u3002\u6362\u53e5\u8bdd\u8bf4\uff0c\u7c7b\u578b\u4fdd\u62a4\u53ef\u4ee5\u4fdd\u8bc1\u4e00\u4e2a\u5b57\u7b26\u4e32\u662f\u4e00\u4e2a\u5b57\u7b26\u4e32\uff0c\u5c3d\u7ba1\u5b83\u7684\u503c\u4e5f\u53ef\u4ee5\u662f\u4e00\u4e2a\u6570\u503c\u3002\u7c7b\u578b\u4fdd\u62a4\u4e0e\u7279\u6027\u68c0\u6d4b\u5e76\u4e0d\u662f\u5b8c\u5168\u4e0d\u540c\uff0c\u5176\u4e3b\u8981\u601d\u60f3\u662f\u5c1d\u8bd5\u68c0\u6d4b\u5c5e\u6027\u3001\u65b9\u6cd5\u6216\u539f\u578b\uff0c\u4ee5\u786e\u5b9a\u5982\u4f55\u5904\u7406\u503c\u3002\u76ee\u524d\u4e3b\u8981\u6709\u56db\u79cd\u7684\u65b9\u5f0f\u6765\u5b9e\u73b0\u7c7b\u578b\u4fdd\u62a4\uff1a<\/p>\n<h3>4.1 in \u5173\u952e\u5b57<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">interface Admin {\r\n  name: string;\r\n  privileges: string[];\r\n}\r\n\r\ninterface Employee {\r\n  name: string;\r\n  startDate: Date;\r\n}\r\n\r\ntype UnknownEmployee = Employee | Admin;\r\n\r\nfunction printEmployeeInformation(emp: UnknownEmployee) {\r\n  console.log(\"Name: \" + emp.name);\r\n  if (\"privileges\" in emp) {\r\n    console.log(\"Privileges: \" + emp.privileges);\r\n  }\r\n  if (\"startDate\" in emp) {\r\n    console.log(\"Start Date: \" + emp.startDate);\r\n  }\r\n}<\/code><\/pre>\n<\/div>\n<h3>4.2 typeof \u5173\u952e\u5b57<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">function padLeft(value: string, padding: string | number) {\r\n  if (typeof padding === \"number\") {\r\n      return Array(padding + 1).join(\" \") + value;\r\n  }\r\n  if (typeof padding === \"string\") {\r\n      return padding + value;\r\n  }\r\n  throw new Error(`Expected string or number, got '${padding}'.`);\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"xGHgrB7D\"><code>typeof<\/code>\u00a0\u7c7b\u578b\u4fdd\u62a4\u53ea\u652f\u6301\u4e24\u79cd\u5f62\u5f0f\uff1a<code>typeof v === \"typename\"<\/code>\u00a0\u548c\u00a0<code>typeof v !== typename<\/code>\uff0c<code>\"typename\"<\/code>\u00a0\u5fc5\u987b\u662f\u00a0<code>\"number\"<\/code>\uff0c\u00a0<code>\"string\"<\/code>\uff0c\u00a0<code>\"boolean\"<\/code>\u00a0\u6216\u00a0<code>\"symbol\"<\/code>\u3002 \u4f46\u662f TypeScript \u5e76\u4e0d\u4f1a\u963b\u6b62\u4f60\u4e0e\u5176\u5b83\u5b57\u7b26\u4e32\u6bd4\u8f83\uff0c\u8bed\u8a00\u4e0d\u4f1a\u628a\u90a3\u4e9b\u8868\u8fbe\u5f0f\u8bc6\u522b\u4e3a\u7c7b\u578b\u4fdd\u62a4\u3002<\/p>\n<h3>4.3 instanceof \u5173\u952e\u5b57<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">interface Padder {\r\n  getPaddingString(): string;\r\n}\r\n\r\nclass SpaceRepeatingPadder implements Padder {\r\n  constructor(private numSpaces: number) {}\r\n  getPaddingString() {\r\n    return Array(this.numSpaces + 1).join(\" \");\r\n  }\r\n}\r\n\r\nclass StringPadder implements Padder {\r\n  constructor(private value: string) {}\r\n  getPaddingString() {\r\n    return this.value;\r\n  }\r\n}\r\n\r\nlet padder: Padder = new SpaceRepeatingPadder(6);\r\n\r\nif (padder instanceof SpaceRepeatingPadder) {\r\n  \/\/ padder\u7684\u7c7b\u578b\u6536\u7a84\u4e3a 'SpaceRepeatingPadder'\r\n}<\/code><\/pre>\n<\/div>\n<h3>4.4 \u81ea\u5b9a\u4e49\u7c7b\u578b\u4fdd\u62a4\u7684\u7c7b\u578b\u8c13\u8bcd<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">function isNumber(x: any): x is number {\r\n  return typeof x === \"number\";\r\n}\r\n\r\nfunction isString(x: any): x is string {\r\n  return typeof x === \"string\";\r\n}<\/code><\/pre>\n<\/div>\n<h3>\u4e94\u3001\u8054\u5408\u7c7b\u578b\u548c\u7c7b\u578b\u522b\u540d<\/h3>\n<h3>5.1 \u8054\u5408\u7c7b\u578b<\/h3>\n<p data-pid=\"qLNEBHZj\">\u8054\u5408\u7c7b\u578b\u901a\u5e38\u4e0e\u00a0<code>null<\/code>\u00a0\u6216\u00a0<code>undefined<\/code>\u00a0\u4e00\u8d77\u4f7f\u7528\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">const sayHello = (name: string | undefined) =&gt; {\r\n  \/* ... *\/\r\n};<\/code><\/pre>\n<\/div>\n<p data-pid=\"-ZKu6hnf\">\u4f8b\u5982\uff0c\u8fd9\u91cc\u00a0<code>name<\/code>\u00a0\u7684\u7c7b\u578b\u662f\u00a0<code>string | undefined<\/code>\u00a0\u610f\u5473\u7740\u53ef\u4ee5\u5c06\u00a0<code>string<\/code>\u00a0\u6216\u00a0<code>undefined<\/code>\u00a0\u7684\u503c\u4f20\u9012\u7ed9<code>sayHello<\/code>\u51fd\u6570\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">sayHello(\"Semlinker\");\r\nsayHello(undefined);<\/code><\/pre>\n<\/div>\n<p data-pid=\"YcrxaeRb\">\u901a\u8fc7\u8fd9\u4e2a\u793a\u4f8b\uff0c\u4f60\u53ef\u4ee5\u51ed\u76f4\u89c9\u77e5\u9053\u7c7b\u578b A \u548c\u7c7b\u578b B \u8054\u5408\u540e\u7684\u7c7b\u578b\u662f\u540c\u65f6\u63a5\u53d7 A \u548c B \u503c\u7684\u7c7b\u578b\u3002<\/p>\n<h3>5.2 \u53ef\u8fa8\u8bc6\u8054\u5408<\/h3>\n<p data-pid=\"wWWwQF_1\">TypeScript \u53ef\u8fa8\u8bc6\u8054\u5408\uff08Discriminated Unions\uff09\u7c7b\u578b\uff0c\u4e5f\u79f0\u4e3a\u4ee3\u6570\u6570\u636e\u7c7b\u578b\u6216\u6807\u7b7e\u8054\u5408\u7c7b\u578b\u3002<b>\u5b83\u5305\u542b 3 \u4e2a\u8981\u70b9\uff1a\u53ef\u8fa8\u8bc6\u3001\u8054\u5408\u7c7b\u578b\u548c\u7c7b\u578b\u5b88\u536b\u3002<\/b><\/p>\n<p data-pid=\"2bHHYdmR\">\u8fd9\u79cd\u7c7b\u578b\u7684\u672c\u8d28\u662f\u7ed3\u5408\u8054\u5408\u7c7b\u578b\u548c\u5b57\u9762\u91cf\u7c7b\u578b\u7684\u4e00\u79cd\u7c7b\u578b\u4fdd\u62a4\u65b9\u6cd5\u3002<b>\u5982\u679c\u4e00\u4e2a\u7c7b\u578b\u662f\u591a\u4e2a\u7c7b\u578b\u7684\u8054\u5408\u7c7b\u578b\uff0c\u4e14\u591a\u4e2a\u7c7b\u578b\u542b\u6709\u4e00\u4e2a\u516c\u5171\u5c5e\u6027\uff0c\u90a3\u4e48\u5c31\u53ef\u4ee5\u5229\u7528\u8fd9\u4e2a\u516c\u5171\u5c5e\u6027\uff0c\u6765\u521b\u5efa\u4e0d\u540c\u7684\u7c7b\u578b\u4fdd\u62a4\u533a\u5757\u3002<\/b><\/p>\n<p data-pid=\"xyPAlMZy\"><b>1.\u53ef\u8fa8\u8bc6<\/b><\/p>\n<p data-pid=\"hXvFG11W\">\u53ef\u8fa8\u8bc6\u8981\u6c42\u8054\u5408\u7c7b\u578b\u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\u90fd\u542b\u6709\u4e00\u4e2a\u5355\u4f8b\u7c7b\u578b\u5c5e\u6027\uff0c\u6bd4\u5982\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">enum CarTransmission {\r\n  Automatic = 200,\r\n  Manual = 300\r\n}\r\n\r\ninterface Motorcycle {\r\n  vType: \"motorcycle\"; \/\/ discriminant\r\n  make: number; \/\/ year\r\n}\r\n\r\ninterface Car {\r\n  vType: \"car\"; \/\/ discriminant\r\n  transmission: CarTransmission\r\n}\r\n\r\ninterface Truck {\r\n  vType: \"truck\"; \/\/ discriminant\r\n  capacity: number; \/\/ in tons\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"SKMKpSX8\">\u5728\u4e0a\u8ff0\u4ee3\u7801\u4e2d\uff0c\u6211\u4eec\u5206\u522b\u5b9a\u4e49\u4e86\u00a0<code>Motorcycle<\/code>\u3001\u00a0<code>Car<\/code>\u00a0\u548c\u00a0<code>Truck<\/code>\u00a0\u4e09\u4e2a\u63a5\u53e3\uff0c\u5728\u8fd9\u4e9b\u63a5\u53e3\u4e2d\u90fd\u5305\u542b\u4e00\u4e2a\u00a0<code>vType<\/code>\u5c5e\u6027\uff0c\u8be5\u5c5e\u6027\u88ab\u79f0\u4e3a\u53ef\u8fa8\u8bc6\u7684\u5c5e\u6027\uff0c\u800c\u5176\u5b83\u7684\u5c5e\u6027\u53ea\u8ddf\u7279\u6027\u7684\u63a5\u53e3\u76f8\u5173\u3002<\/p>\n<p data-pid=\"Dp7Z5MeC\"><b>2.\u8054\u5408\u7c7b\u578b<\/b><\/p>\n<p data-pid=\"mS98Zpow\">\u57fa\u4e8e\u524d\u9762\u5b9a\u4e49\u4e86\u4e09\u4e2a\u63a5\u53e3\uff0c\u6211\u4eec\u53ef\u4ee5\u521b\u5efa\u4e00\u4e2a\u00a0<code>Vehicle<\/code>\u00a0\u8054\u5408\u7c7b\u578b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">type Vehicle = Motorcycle | Car | Truck;<\/code><\/pre>\n<\/div>\n<p data-pid=\"E_J6xeNp\">\u73b0\u5728\u6211\u4eec\u5c31\u53ef\u4ee5\u5f00\u59cb\u4f7f\u7528\u00a0<code>Vehicle<\/code>\u00a0\u8054\u5408\u7c7b\u578b\uff0c\u5bf9\u4e8e\u00a0<code>Vehicle<\/code>\u00a0\u7c7b\u578b\u7684\u53d8\u91cf\uff0c\u5b83\u53ef\u4ee5\u8868\u793a\u4e0d\u540c\u7c7b\u578b\u7684\u8f66\u8f86\u3002<\/p>\n<p data-pid=\"QfV3zBHa\"><b>3.\u7c7b\u578b\u5b88\u536b<\/b><\/p>\n<p data-pid=\"rXMsYs2g\">\u4e0b\u9762\u6211\u4eec\u6765\u5b9a\u4e49\u4e00\u4e2a\u00a0<code>evaluatePrice<\/code>\u00a0\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u7528\u4e8e\u6839\u636e\u8f66\u8f86\u7684\u7c7b\u578b\u3001\u5bb9\u91cf\u548c\u8bc4\u4f30\u56e0\u5b50\u6765\u8ba1\u7b97\u4ef7\u683c\uff0c\u5177\u4f53\u5b9e\u73b0\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">const EVALUATION_FACTOR = Math.PI; \r\nfunction evaluatePrice(vehicle: Vehicle) {\r\n  return vehicle.capacity * EVALUATION_FACTOR;\r\n}\r\n\r\nconst myTruck: Truck = { vType: \"truck\", capacity: 9.5 };\r\nevaluatePrice(myTruck);<\/code><\/pre>\n<\/div>\n<p data-pid=\"OD6zoYca\">\u5bf9\u4e8e\u4ee5\u4e0a\u4ee3\u7801\uff0cTypeScript \u7f16\u8bd1\u5668\u5c06\u4f1a\u63d0\u793a\u4ee5\u4e0b\u9519\u8bef\u4fe1\u606f\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">Property 'capacity' does not exist on type 'Vehicle'.\r\nProperty 'capacity' does not exist on type 'Motorcycle'.<\/code><\/pre>\n<\/div>\n<p data-pid=\"OuXKeNqB\">\u539f\u56e0\u662f\u5728 Motorcycle \u63a5\u53e3\u4e2d\uff0c\u5e76\u4e0d\u5b58\u5728\u00a0<code>capacity<\/code>\u00a0\u5c5e\u6027\uff0c\u800c\u5bf9\u4e8e Car \u63a5\u53e3\u6765\u8bf4\uff0c\u5b83\u4e5f\u4e0d\u5b58\u5728\u00a0<code>capacity<\/code>\u00a0\u5c5e\u6027\u3002\u90a3\u4e48\uff0c\u73b0\u5728\u6211\u4eec\u5e94\u8be5\u5982\u4f55\u89e3\u51b3\u4ee5\u4e0a\u95ee\u9898\u5462\uff1f\u8fd9\u65f6\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u7c7b\u578b\u5b88\u536b\u3002\u4e0b\u9762\u6211\u4eec\u6765\u91cd\u6784\u4e00\u4e0b\u524d\u9762\u5b9a\u4e49\u7684\u00a0<code>evaluatePrice<\/code>\u00a0\u65b9\u6cd5\uff0c\u91cd\u6784\u540e\u7684\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">function evaluatePrice(vehicle: Vehicle) {\r\n  switch(vehicle.vType) {\r\n    case \"car\":\r\n      return vehicle.transmission * EVALUATION_FACTOR;\r\n    case \"truck\":\r\n      return vehicle.capacity * EVALUATION_FACTOR;\r\n    case \"motorcycle\":\r\n      return vehicle.make * EVALUATION_FACTOR;\r\n  }\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"W-LBk9oo\">\u5728\u4ee5\u4e0a\u4ee3\u7801\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528\u00a0<code>switch<\/code>\u00a0\u548c\u00a0<code>case<\/code>\u00a0\u8fd0\u7b97\u7b26\u6765\u5b9e\u73b0\u7c7b\u578b\u5b88\u536b\uff0c\u4ece\u800c\u786e\u4fdd\u5728\u00a0<code>evaluatePrice<\/code>\u00a0\u65b9\u6cd5\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u5b89\u5168\u5730\u8bbf\u95ee\u00a0<code>vehicle<\/code>\u00a0\u5bf9\u8c61\u4e2d\u7684\u6240\u5305\u542b\u7684\u5c5e\u6027\uff0c\u6765\u6b63\u786e\u7684\u8ba1\u7b97\u8be5\u8f66\u8f86\u7c7b\u578b\u6240\u5bf9\u5e94\u7684\u4ef7\u683c\u3002<\/p>\n<h3>5.3 \u7c7b\u578b\u522b\u540d<\/h3>\n<p data-pid=\"YcVe882s\">\u7c7b\u578b\u522b\u540d\u7528\u6765\u7ed9\u4e00\u4e2a\u7c7b\u578b\u8d77\u4e2a\u65b0\u540d\u5b57\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">type Message = string | string[];\r\n\r\nlet greet = (message: Message) =&gt; {\r\n  \/\/ ...\r\n};<\/code><\/pre>\n<\/div>\n<h3>\u516d\u3001\u4ea4\u53c9\u7c7b\u578b<\/h3>\n<p data-pid=\"9fZs9dfz\">TypeScript \u4ea4\u53c9\u7c7b\u578b\u662f\u5c06\u591a\u4e2a\u7c7b\u578b\u5408\u5e76\u4e3a\u4e00\u4e2a\u7c7b\u578b\u3002 \u8fd9\u8ba9\u6211\u4eec\u53ef\u4ee5\u628a\u73b0\u6709\u7684\u591a\u79cd\u7c7b\u578b\u53e0\u52a0\u5230\u4e00\u8d77\u6210\u4e3a\u4e00\u79cd\u7c7b\u578b\uff0c\u5b83\u5305\u542b\u4e86\u6240\u9700\u7684\u6240\u6709\u7c7b\u578b\u7684\u7279\u6027\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">interface IPerson {\r\n  id: string;\r\n  age: number;\r\n}\r\n\r\ninterface IWorker {\r\n  companyId: string;\r\n}\r\n\r\ntype IStaff = IPerson &amp; IWorker;\r\n\r\nconst staff: IStaff = {\r\n  id: 'E1006',\r\n  age: 33,\r\n  companyId: 'EFT'\r\n};\r\n\r\nconsole.dir(staff)<\/code><\/pre>\n<\/div>\n<p data-pid=\"v5Q-q-dL\">\u5728\u4e0a\u9762\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u9996\u5148\u4e3a IPerson \u548c IWorker \u7c7b\u578b\u5b9a\u4e49\u4e86\u4e0d\u540c\u7684\u6210\u5458\uff0c\u7136\u540e\u901a\u8fc7\u00a0<code>&amp;<\/code>\u00a0\u8fd0\u7b97\u7b26\u5b9a\u4e49\u4e86 IStaff \u4ea4\u53c9\u7c7b\u578b\uff0c\u6240\u4ee5\u8be5\u7c7b\u578b\u540c\u65f6\u62e5\u6709 IPerson \u548c IWorker \u8fd9\u4e24\u79cd\u7c7b\u578b\u7684\u6210\u5458\u3002<\/p>\n<h3>\u4e03\u3001TypeScript \u51fd\u6570<\/h3>\n<h3>7.1 TypeScript \u51fd\u6570\u4e0e JavaScript \u51fd\u6570\u7684\u533a\u522b<\/h3>\n<p data-pid=\"S5NXxZrj\">TypeScriptJavaScript\u542b\u6709\u7c7b\u578b\u65e0\u7c7b\u578b\u7bad\u5934\u51fd\u6570\u7bad\u5934\u51fd\u6570\uff08ES2015\uff09\u51fd\u6570\u7c7b\u578b\u65e0\u51fd\u6570\u7c7b\u578b\u5fc5\u586b\u548c\u53ef\u9009\u53c2\u6570\u6240\u6709\u53c2\u6570\u90fd\u662f\u53ef\u9009\u7684\u9ed8\u8ba4\u53c2\u6570\u9ed8\u8ba4\u53c2\u6570\u5269\u4f59\u53c2\u6570\u5269\u4f59\u53c2\u6570\u51fd\u6570\u91cd\u8f7d\u65e0\u51fd\u6570\u91cd\u8f7d<\/p>\n<h3>7.2 \u7bad\u5934\u51fd\u6570<\/h3>\n<p data-pid=\"qTv_2obq\"><b>1.\u5e38\u89c1\u8bed\u6cd5<\/b><\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">myBooks.forEach(() =&gt; console.log('reading'));\r\n\r\nmyBooks.forEach(title =&gt; console.log(title));\r\n\r\nmyBooks.forEach((title, idx, arr) =&gt;\r\n  console.log(idx + '-' + title);\r\n);\r\n\r\nmyBooks.forEach((title, idx, arr) =&gt; {\r\n  console.log(idx + '-' + title);\r\n});<\/code><\/pre>\n<\/div>\n<p data-pid=\"QibDVyMI\"><b>2.\u4f7f\u7528\u793a\u4f8b<\/b><\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">\/\/ \u672a\u4f7f\u7528\u7bad\u5934\u51fd\u6570\r\nfunction Book() {\r\n  let self = this;\r\n  self.publishDate = 2016;\r\n  setInterval(function () {\r\n    console.log(self.publishDate);\r\n  }, 1000);\r\n}\r\n\r\n\/\/ \u4f7f\u7528\u7bad\u5934\u51fd\u6570\r\nfunction Book() {\r\n  this.publishDate = 2016;\r\n  setInterval(() =&gt; {\r\n    console.log(this.publishDate);\r\n  }, 1000);\r\n}<\/code><\/pre>\n<\/div>\n<h3>7.3 \u53c2\u6570\u7c7b\u578b\u548c\u8fd4\u56de\u7c7b\u578b<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">function createUserId(name: string, id: number): string {\r\n  return name + id;\r\n}<\/code><\/pre>\n<\/div>\n<h3>7.4 \u51fd\u6570\u7c7b\u578b<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let IdGenerator: (chars: string, nums: number) =&gt; string;\r\n\r\nfunction createUserId(name: string, id: number): string {\r\n  return name + id;\r\n}\r\n\r\nIdGenerator = createUserId;<\/code><\/pre>\n<\/div>\n<h3>7.5 \u53ef\u9009\u53c2\u6570\u53ca\u9ed8\u8ba4\u53c2\u6570<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">\/\/ \u53ef\u9009\u53c2\u6570\r\nfunction createUserId(name: string, id: number, age?: number): string {\r\n  return name + id;\r\n}\r\n\r\n\/\/ \u9ed8\u8ba4\u53c2\u6570\r\nfunction createUserId(\r\n  name: string = \"Semlinker\",\r\n  id: number,\r\n  age?: number\r\n): string {\r\n  return name + id;\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"fZNTitQr\">\u5728\u58f0\u660e\u51fd\u6570\u65f6\uff0c\u53ef\u4ee5\u901a\u8fc7\u00a0<code>?<\/code>\u00a0\u53f7\u6765\u5b9a\u4e49\u53ef\u9009\u53c2\u6570\uff0c\u6bd4\u5982\u00a0<code>age?: number<\/code>\u00a0\u8fd9\u79cd\u5f62\u5f0f\u3002\u5728\u5b9e\u9645\u4f7f\u7528\u65f6\uff0c\u9700\u8981\u6ce8\u610f\u7684\u662f\u53ef\u9009\u53c2\u6570\u8981\u653e\u5728\u666e\u901a\u53c2\u6570\u7684\u540e\u9762\uff0c\u4e0d\u7136\u4f1a\u5bfc\u81f4\u7f16\u8bd1\u9519\u8bef\u3002<\/p>\n<h3>7.6 \u5269\u4f59\u53c2\u6570<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">function push(array, ...items) {\r\n  items.forEach(function (item) {\r\n    array.push(item);\r\n  });\r\n}\r\n\r\nlet a = [];\r\npush(a, 1, 2, 3);<\/code><\/pre>\n<\/div>\n<h3>7.7 \u51fd\u6570\u91cd\u8f7d<\/h3>\n<p data-pid=\"kru_Kp1g\">\u51fd\u6570\u91cd\u8f7d\u6216\u65b9\u6cd5\u91cd\u8f7d\u662f\u4f7f\u7528\u76f8\u540c\u540d\u79f0\u548c\u4e0d\u540c\u53c2\u6570\u6570\u91cf\u6216\u7c7b\u578b\u521b\u5efa\u591a\u4e2a\u65b9\u6cd5\u7684\u4e00\u79cd\u80fd\u529b\u3002\u8981\u89e3\u51b3\u524d\u9762\u9047\u5230\u7684\u95ee\u9898\uff0c\u65b9\u6cd5\u5c31\u662f\u4e3a\u540c\u4e00\u4e2a\u51fd\u6570\u63d0\u4f9b\u591a\u4e2a\u51fd\u6570\u7c7b\u578b\u5b9a\u4e49\u6765\u8fdb\u884c\u51fd\u6570\u91cd\u8f7d\uff0c\u7f16\u8bd1\u5668\u4f1a\u6839\u636e\u8fd9\u4e2a\u5217\u8868\u53bb\u5904\u7406\u51fd\u6570\u7684\u8c03\u7528\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">function add(a: number, b: number): number;\r\nfunction add(a: string, b: string): string;\r\nfunction add(a: string, b: number): string;\r\nfunction add(a: number, b: string): string;\r\nfunction add(a: Combinable, b: Combinable) {\r\n  if (typeof a === \"string\" || typeof b === \"string\") {\r\n    return a.toString() + b.toString();\r\n  }\r\n  return a + b;\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"l-QRh-4P\">\u5728\u4ee5\u4e0a\u4ee3\u7801\u4e2d\uff0c\u6211\u4eec\u4e3a add \u51fd\u6570\u63d0\u4f9b\u4e86\u591a\u4e2a\u51fd\u6570\u7c7b\u578b\u5b9a\u4e49\uff0c\u4ece\u800c\u5b9e\u73b0\u51fd\u6570\u7684\u91cd\u8f7d\u3002\u4e4b\u540e\uff0c\u53ef\u6076\u7684\u9519\u8bef\u6d88\u606f\u53c8\u6d88\u5931\u4e86\uff0c\u56e0\u4e3a\u8fd9\u65f6 result \u53d8\u91cf\u7684\u7c7b\u578b\u662f\u00a0<code>string<\/code>\u00a0\u7c7b\u578b\u3002\u5728 TypeScript \u4e2d\u9664\u4e86\u53ef\u4ee5\u91cd\u8f7d\u666e\u901a\u51fd\u6570\u4e4b\u5916\uff0c\u6211\u4eec\u8fd8\u53ef\u4ee5\u91cd\u8f7d\u7c7b\u4e2d\u7684\u6210\u5458\u65b9\u6cd5\u3002<\/p>\n<p data-pid=\"dMotnvIB\">\u65b9\u6cd5\u91cd\u8f7d\u662f\u6307\u5728\u540c\u4e00\u4e2a\u7c7b\u4e2d\u65b9\u6cd5\u540c\u540d\uff0c\u53c2\u6570\u4e0d\u540c\uff08\u53c2\u6570\u7c7b\u578b\u4e0d\u540c\u3001\u53c2\u6570\u4e2a\u6570\u4e0d\u540c\u6216\u53c2\u6570\u4e2a\u6570\u76f8\u540c\u65f6\u53c2\u6570\u7684\u5148\u540e\u987a\u5e8f\u4e0d\u540c\uff09\uff0c\u8c03\u7528\u65f6\u6839\u636e\u5b9e\u53c2\u7684\u5f62\u5f0f\uff0c\u9009\u62e9\u4e0e\u5b83\u5339\u914d\u7684\u65b9\u6cd5\u6267\u884c\u64cd\u4f5c\u7684\u4e00\u79cd\u6280\u672f\u3002\u6240\u4ee5\u7c7b\u4e2d\u6210\u5458\u65b9\u6cd5\u6ee1\u8db3\u91cd\u8f7d\u7684\u6761\u4ef6\u662f\uff1a\u5728\u540c\u4e00\u4e2a\u7c7b\u4e2d\uff0c\u65b9\u6cd5\u540d\u76f8\u540c\u4e14\u53c2\u6570\u5217\u8868\u4e0d\u540c\u3002\u4e0b\u9762\u6211\u4eec\u6765\u4e3e\u4e00\u4e2a\u6210\u5458\u65b9\u6cd5\u91cd\u8f7d\u7684\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">class Calculator {\r\n  add(a: number, b: number): number;\r\n  add(a: string, b: string): string;\r\n  add(a: string, b: number): string;\r\n  add(a: number, b: string): string;\r\n  add(a: Combinable, b: Combinable) {\r\n    if (typeof a === \"string\" || typeof b === \"string\") {\r\n      return a.toString() + b.toString();\r\n    }\r\n    return a + b;\r\n  }\r\n}\r\n\r\nconst calculator = new Calculator();\r\nconst result = calculator.add(\"Semlinker\", \" Kakuqo\");<\/code><\/pre>\n<\/div>\n<p data-pid=\"ApRP4cOn\">\u8fd9\u91cc\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5f53 TypeScript \u7f16\u8bd1\u5668\u5904\u7406\u51fd\u6570\u91cd\u8f7d\u65f6\uff0c\u5b83\u4f1a\u67e5\u627e\u91cd\u8f7d\u5217\u8868\uff0c\u5c1d\u8bd5\u4f7f\u7528\u7b2c\u4e00\u4e2a\u91cd\u8f7d\u5b9a\u4e49\u3002 \u5982\u679c\u5339\u914d\u7684\u8bdd\u5c31\u4f7f\u7528\u8fd9\u4e2a\u3002 \u56e0\u6b64\uff0c\u5728\u5b9a\u4e49\u91cd\u8f7d\u7684\u65f6\u5019\uff0c\u4e00\u5b9a\u8981\u628a\u6700\u7cbe\u786e\u7684\u5b9a\u4e49\u653e\u5728\u6700\u524d\u9762\u3002\u53e6\u5916\u5728 Calculator \u7c7b\u4e2d\uff0c<code>add(a: Combinable, b: Combinable){ }<\/code>\u00a0\u5e76\u4e0d\u662f\u91cd\u8f7d\u5217\u8868\u7684\u4e00\u90e8\u5206\uff0c\u56e0\u6b64\u5bf9\u4e8e add \u6210\u5458\u65b9\u6cd5\u6765\u8bf4\uff0c\u6211\u4eec\u53ea\u5b9a\u4e49\u4e86\u56db\u4e2a\u91cd\u8f7d\u65b9\u6cd5\u3002<\/p>\n<h3>\u516b\u3001TypeScript \u6570\u7ec4<\/h3>\n<h3>8.1 \u6570\u7ec4\u89e3\u6784<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let x: number; let y: number; let z: number;\r\nlet five_array = [0,1,2,3,4];\r\n[x,y,z] = five_array;<\/code><\/pre>\n<\/div>\n<h3>8.2 \u6570\u7ec4\u5c55\u5f00\u8fd0\u7b97\u7b26<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let two_array = [0, 1];\r\nlet five_array = [...two_array, 2, 3, 4];<\/code><\/pre>\n<\/div>\n<h3>8.3 \u6570\u7ec4\u904d\u5386<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let colors: string[] = [\"red\", \"green\", \"blue\"];\r\nfor (let i of colors) {\r\n  console.log(i);\r\n}<\/code><\/pre>\n<\/div>\n<h3>\u4e5d\u3001TypeScript \u5bf9\u8c61<\/h3>\n<h3>9.1 \u5bf9\u8c61\u89e3\u6784<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let person = {\r\n  name: \"Semlinker\",\r\n  gender: \"Male\",\r\n};\r\n\r\nlet { name, gender } = person;<\/code><\/pre>\n<\/div>\n<h3>9.2 \u5bf9\u8c61\u5c55\u5f00\u8fd0\u7b97\u7b26<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let person = {\r\n  name: \"Semlinker\",\r\n  gender: \"Male\",\r\n  address: \"Xiamen\",\r\n};\r\n\r\n\/\/ \u7ec4\u88c5\u5bf9\u8c61\r\nlet personWithAge = { ...person, age: 33 };\r\n\r\n\/\/ \u83b7\u53d6\u9664\u4e86\u67d0\u4e9b\u9879\u5916\u7684\u5176\u5b83\u9879\r\nlet { name, ...rest } = person;<\/code><\/pre>\n<\/div>\n<h3>\u5341\u3001TypeScript \u63a5\u53e3<\/h3>\n<p data-pid=\"emVcSAf2\">\u5728\u9762\u5411\u5bf9\u8c61\u8bed\u8a00\u4e2d\uff0c\u63a5\u53e3\u662f\u4e00\u4e2a\u5f88\u91cd\u8981\u7684\u6982\u5ff5\uff0c\u5b83\u662f\u5bf9\u884c\u4e3a\u7684\u62bd\u8c61\uff0c\u800c\u5177\u4f53\u5982\u4f55\u884c\u52a8\u9700\u8981\u7531\u7c7b\u53bb\u5b9e\u73b0\u3002<\/p>\n<p data-pid=\"gEpEpmBJ\">TypeScript \u4e2d\u7684\u63a5\u53e3\u662f\u4e00\u4e2a\u975e\u5e38\u7075\u6d3b\u7684\u6982\u5ff5\uff0c\u9664\u4e86\u53ef\u7528\u4e8e<a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=https%3A\/\/ts.xcatliu.com\/advanced\/class-and-interfaces.html%23%25E7%25B1%25BB%25E5%25AE%259E%25E7%258E%25B0%25E6%258E%25A5%25E5%258F%25A3\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">\u5bf9\u7c7b\u7684\u4e00\u90e8\u5206\u884c\u4e3a\u8fdb\u884c\u62bd\u8c61<\/a>\u4ee5\u5916\uff0c\u4e5f\u5e38\u7528\u4e8e\u5bf9\u300c\u5bf9\u8c61\u7684\u5f62\u72b6\uff08Shape\uff09\u300d\u8fdb\u884c\u63cf\u8ff0\u3002<\/p>\n<h3>10.1 \u5bf9\u8c61\u7684\u5f62\u72b6<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">interface Person {\r\n  name: string;\r\n  age: number;\r\n}\r\n\r\nlet Semlinker: Person = {\r\n  name: \"Semlinker\",\r\n  age: 33,\r\n};<\/code><\/pre>\n<\/div>\n<h3>10.2 \u53ef\u9009 | \u53ea\u8bfb\u5c5e\u6027<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">interface Person {\r\n  readonly name: string;\r\n  age?: number;\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"I-lotTFd\">\u53ea\u8bfb\u5c5e\u6027\u7528\u4e8e\u9650\u5236\u53ea\u80fd\u5728\u5bf9\u8c61\u521a\u521a\u521b\u5efa\u7684\u65f6\u5019\u4fee\u6539\u5176\u503c\u3002\u6b64\u5916 TypeScript \u8fd8\u63d0\u4f9b\u4e86\u00a0<code>ReadonlyArray&lt;T&gt;<\/code>\u00a0\u7c7b\u578b\uff0c\u5b83\u4e0e\u00a0<code>Array&lt;T&gt;<\/code>\u00a0\u76f8\u4f3c\uff0c\u53ea\u662f\u628a\u6240\u6709\u53ef\u53d8\u65b9\u6cd5\u53bb\u6389\u4e86\uff0c\u56e0\u6b64\u53ef\u4ee5\u786e\u4fdd\u6570\u7ec4\u521b\u5efa\u540e\u518d\u4e5f\u4e0d\u80fd\u88ab\u4fee\u6539\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let a: number[] = [1, 2, 3, 4];\r\nlet ro: ReadonlyArray&lt;number&gt; = a;\r\nro[0] = 12; \/\/ error!\r\nro.push(5); \/\/ error!\r\nro.length = 100; \/\/ error!\r\na = ro; \/\/ error!<\/code><\/pre>\n<\/div>\n<h3>\u5341\u4e00\u3001TypeScript \u7c7b<\/h3>\n<h3>11.1 \u7c7b\u7684\u5c5e\u6027\u4e0e\u65b9\u6cd5<\/h3>\n<p data-pid=\"WIDYVQ0p\">\u5728\u9762\u5411\u5bf9\u8c61\u8bed\u8a00\u4e2d\uff0c\u7c7b\u662f\u4e00\u79cd\u9762\u5411\u5bf9\u8c61\u8ba1\u7b97\u673a\u7f16\u7a0b\u8bed\u8a00\u7684\u6784\u9020\uff0c\u662f\u521b\u5efa\u5bf9\u8c61\u7684\u84dd\u56fe\uff0c\u63cf\u8ff0\u4e86\u6240\u521b\u5efa\u7684\u5bf9\u8c61\u5171\u540c\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\u3002<\/p>\n<p data-pid=\"j-WZe5j5\">\u5728 TypeScript \u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u00a0<code>Class<\/code>\u00a0\u5173\u952e\u5b57\u6765\u5b9a\u4e49\u4e00\u4e2a\u7c7b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">class Greeter {\r\n  \/\/ \u9759\u6001\u5c5e\u6027\r\n  static cname: string = \"Greeter\";\r\n  \/\/ \u6210\u5458\u5c5e\u6027\r\n  greeting: string;\r\n\r\n  \/\/ \u6784\u9020\u51fd\u6570 - \u6267\u884c\u521d\u59cb\u5316\u64cd\u4f5c\r\n  constructor(message: string) {\r\n    this.greeting = message;\r\n  }\r\n\r\n  \/\/ \u9759\u6001\u65b9\u6cd5\r\n  static getClassName() {\r\n    return \"Class name is Greeter\";\r\n  }\r\n\r\n  \/\/ \u6210\u5458\u65b9\u6cd5\r\n  greet() {\r\n    return \"Hello, \" + this.greeting;\r\n  }\r\n}\r\n\r\nlet greeter = new Greeter(\"world\");<\/code><\/pre>\n<\/div>\n<p data-pid=\"ilyUmTRC\">\u90a3\u4e48\u6210\u5458\u5c5e\u6027\u4e0e\u9759\u6001\u5c5e\u6027\uff0c\u6210\u5458\u65b9\u6cd5\u4e0e\u9759\u6001\u65b9\u6cd5\u6709\u4ec0\u4e48\u533a\u522b\u5462\uff1f\u8fd9\u91cc\u65e0\u9700\u8fc7\u591a\u89e3\u91ca\uff0c\u6211\u4eec\u76f4\u63a5\u770b\u4e00\u4e0b\u4ee5\u4e0b\u7f16\u8bd1\u751f\u6210\u7684 ES5 \u4ee3\u7801\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-js\"><span class=\"s2\">\"use strict\"<\/span><span class=\"p\">;<\/span>\r\n<span class=\"kd\">var<\/span> <span class=\"nx\">Greeter<\/span> <span class=\"o\">=<\/span> <span class=\"cm\">\/** @class *\/<\/span> <span class=\"p\">(<\/span><span class=\"kd\">function<\/span> <span class=\"p\">()<\/span> <span class=\"p\">{<\/span>\r\n    <span class=\"c1\">\/\/ \u6784\u9020\u51fd\u6570 - \u6267\u884c\u521d\u59cb\u5316\u64cd\u4f5c\r\n<\/span>    <span class=\"kd\">function<\/span> <span class=\"nx\">Greeter<\/span><span class=\"p\">(<\/span><span class=\"nx\">message<\/span><span class=\"p\">)<\/span> <span class=\"p\">{<\/span>\r\n        <span class=\"k\">this<\/span><span class=\"p\">.<\/span><span class=\"nx\">greeting<\/span> <span class=\"o\">=<\/span> <span class=\"nx\">message<\/span><span class=\"p\">;<\/span>\r\n    <span class=\"p\">}<\/span>\r\n    <span class=\"c1\">\/\/ \u9759\u6001\u65b9\u6cd5\r\n<\/span>    <span class=\"nx\">Greeter<\/span><span class=\"p\">.<\/span><span class=\"nx\">getClassName<\/span> <span class=\"o\">=<\/span> <span class=\"kd\">function<\/span> <span class=\"p\">()<\/span> <span class=\"p\">{<\/span>\r\n        <span class=\"k\">return<\/span> <span class=\"s2\">\"Class name is Greeter\"<\/span><span class=\"p\">;<\/span>\r\n    <span class=\"p\">};<\/span>\r\n    <span class=\"c1\">\/\/ \u6210\u5458\u65b9\u6cd5\r\n<\/span>    <span class=\"nx\">Greeter<\/span><span class=\"p\">.<\/span><span class=\"nx\">prototype<\/span><span class=\"p\">.<\/span><span class=\"nx\">greet<\/span> <span class=\"o\">=<\/span> <span class=\"kd\">function<\/span> <span class=\"p\">()<\/span> <span class=\"p\">{<\/span>\r\n        <span class=\"k\">return<\/span> <span class=\"s2\">\"Hello, \"<\/span> <span class=\"o\">+<\/span> <span class=\"k\">this<\/span><span class=\"p\">.<\/span><span class=\"nx\">greeting<\/span><span class=\"p\">;<\/span>\r\n    <span class=\"p\">};<\/span>\r\n    <span class=\"c1\">\/\/ \u9759\u6001\u5c5e\u6027\r\n<\/span>    <span class=\"nx\">Greeter<\/span><span class=\"p\">.<\/span><span class=\"nx\">cname<\/span> <span class=\"o\">=<\/span> <span class=\"s2\">\"Greeter\"<\/span><span class=\"p\">;<\/span>\r\n    <span class=\"k\">return<\/span> <span class=\"nx\">Greeter<\/span><span class=\"p\">;<\/span>\r\n<span class=\"p\">}());<\/span>\r\n<span class=\"kd\">var<\/span> <span class=\"nx\">greeter<\/span> <span class=\"o\">=<\/span> <span class=\"k\">new<\/span> <span class=\"nx\">Greeter<\/span><span class=\"p\">(<\/span><span class=\"s2\">\"world\"<\/span><span class=\"p\">);<\/span>\r\n<\/code><\/pre>\n<\/div>\n<h3>11.2 \u8bbf\u95ee\u5668<\/h3>\n<p data-pid=\"0mVHDm9Y\">\u5728 TypeScript \u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u00a0<code>getter<\/code>\u00a0\u548c\u00a0<code>setter<\/code>\u00a0\u65b9\u6cd5\u6765\u5b9e\u73b0\u6570\u636e\u7684\u5c01\u88c5\u548c\u6709\u6548\u6027\u6821\u9a8c\uff0c\u9632\u6b62\u51fa\u73b0\u5f02\u5e38\u6570\u636e\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">let passcode = \"Hello TypeScript\";\r\n\r\nclass Employee {\r\n  private _fullName: string;\r\n\r\n  get fullName(): string {\r\n    return this._fullName;\r\n  }\r\n\r\n  set fullName(newName: string) {\r\n    if (passcode &amp;&amp; passcode == \"Hello TypeScript\") {\r\n      this._fullName = newName;\r\n    } else {\r\n      console.log(\"Error: Unauthorized update of employee!\");\r\n    }\r\n  }\r\n}\r\n\r\nlet employee = new Employee();\r\nemployee.fullName = \"Semlinker\";\r\nif (employee.fullName) {\r\n  console.log(employee.fullName);\r\n}<\/code><\/pre>\n<\/div>\n<h3>11.3 \u7c7b\u7684\u7ee7\u627f<\/h3>\n<p data-pid=\"1iKnFSK6\">\u7ee7\u627f (Inheritance) \u662f\u4e00\u79cd\u8054\u7ed3\u7c7b\u4e0e\u7c7b\u7684\u5c42\u6b21\u6a21\u578b\u3002\u6307\u7684\u662f\u4e00\u4e2a\u7c7b\uff08\u79f0\u4e3a\u5b50\u7c7b\u3001\u5b50\u63a5\u53e3\uff09\u7ee7\u627f\u53e6\u5916\u7684\u4e00\u4e2a\u7c7b\uff08\u79f0\u4e3a\u7236\u7c7b\u3001\u7236\u63a5\u53e3\uff09\u7684\u529f\u80fd\uff0c\u5e76\u53ef\u4ee5\u589e\u52a0\u5b83\u81ea\u5df1\u7684\u65b0\u529f\u80fd\u7684\u80fd\u529b\uff0c\u7ee7\u627f\u662f\u7c7b\u4e0e\u7c7b\u6216\u8005\u63a5\u53e3\u4e0e\u63a5\u53e3\u4e4b\u95f4\u6700\u5e38\u89c1\u7684\u5173\u7cfb\u3002<\/p>\n<p data-pid=\"HJCdBktb\">\u7ee7\u627f\u662f\u4e00\u79cd\u00a0<a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=https%3A\/\/zh.wikipedia.org\/wiki\/Is-a\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">is-a\u00a0<\/a>\u5173\u7cfb\uff1a<\/p>\n<figure data-size=\"normal\"><img decoding=\"async\" class=\"content_image lazy\" src=\"https:\/\/pic3.zhimg.com\/80\/v2-4903c73f6ded1ce7549c3f5c1ffc40b2_1440w.jpg\" width=\"293\" data-caption=\"\" data-size=\"normal\" data-rawwidth=\"293\" data-rawheight=\"204\" data-actualsrc=\"https:\/\/pic3.zhimg.com\/v2-4903c73f6ded1ce7549c3f5c1ffc40b2_b.jpg\" data-lazy-status=\"ok\" \/><\/figure>\n<p data-pid=\"BJqBMIR_\">\u5728 TypeScript \u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u00a0<code>extends<\/code>\u00a0\u5173\u952e\u5b57\u6765\u5b9e\u73b0\u7ee7\u627f\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">class Animal {\r\n  name: string;\r\n  \r\n  constructor(theName: string) {\r\n    this.name = theName;\r\n  }\r\n  \r\n  move(distanceInMeters: number = 0) {\r\n    console.log(`${this.name} moved ${distanceInMeters}m.`);\r\n  }\r\n}\r\n\r\nclass Snake extends Animal {\r\n  constructor(name: string) {\r\n    super(name);\r\n  }\r\n  \r\n  move(distanceInMeters = 5) {\r\n    console.log(\"Slithering...\");\r\n    super.move(distanceInMeters);\r\n  }\r\n}\r\n\r\nlet sam = new Snake(\"Sammy the Python\");\r\nsam.move();<\/code><\/pre>\n<\/div>\n<h3>11.4 ECMAScript \u79c1\u6709\u5b57\u6bb5<\/h3>\n<p data-pid=\"kJEzOjbJ\">\u5728 TypeScript 3.8 \u7248\u672c\u5c31\u5f00\u59cb\u652f\u6301<b>ECMAScript \u79c1\u6709\u5b57\u6bb5<\/b>\uff0c\u4f7f\u7528\u65b9\u5f0f\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">class Person {\r\n  #name: string;\r\n\r\n  constructor(name: string) {\r\n    this.#name = name;\r\n  }\r\n\r\n  greet() {\r\n    console.log(`Hello, my name is ${this.#name}!`);\r\n  }\r\n}\r\n\r\nlet semlinker = new Person(\"Semlinker\");\r\n\r\nsemlinker.#name;\r\n\/\/     ~~~~~\r\n\/\/ Property '#name' is not accessible outside class 'Person'\r\n\/\/ because it has a private identifier.<\/code><\/pre>\n<\/div>\n<p data-pid=\"q124nixC\">\u4e0e\u5e38\u89c4\u5c5e\u6027\uff08\u751a\u81f3\u4f7f\u7528\u00a0<code>private<\/code>\u00a0\u4fee\u9970\u7b26\u58f0\u660e\u7684\u5c5e\u6027\uff09\u4e0d\u540c\uff0c\u79c1\u6709\u5b57\u6bb5\u8981\u7262\u8bb0\u4ee5\u4e0b\u89c4\u5219\uff1a<\/p>\n<ul>\n<li data-pid=\"WRiau_6x\">\u79c1\u6709\u5b57\u6bb5\u4ee5\u00a0<code>#<\/code>\u00a0\u5b57\u7b26\u5f00\u5934\uff0c\u6709\u65f6\u6211\u4eec\u79f0\u4e4b\u4e3a\u79c1\u6709\u540d\u79f0\uff1b<\/li>\n<li data-pid=\"gLGYfsG0\">\u6bcf\u4e2a\u79c1\u6709\u5b57\u6bb5\u540d\u79f0\u90fd\u552f\u4e00\u5730\u9650\u5b9a\u4e8e\u5176\u5305\u542b\u7684\u7c7b\uff1b<\/li>\n<li data-pid=\"FH9rPr4r\">\u4e0d\u80fd\u5728\u79c1\u6709\u5b57\u6bb5\u4e0a\u4f7f\u7528 TypeScript \u53ef\u8bbf\u95ee\u6027\u4fee\u9970\u7b26\uff08\u5982 public \u6216 private\uff09\uff1b<\/li>\n<li data-pid=\"fqGQo4x4\">\u79c1\u6709\u5b57\u6bb5\u4e0d\u80fd\u5728\u5305\u542b\u7684\u7c7b\u4e4b\u5916\u8bbf\u95ee\uff0c\u751a\u81f3\u4e0d\u80fd\u88ab\u68c0\u6d4b\u5230\u3002<\/li>\n<\/ul>\n<h3>\u5341\u4e8c\u3001TypeScript \u6cdb\u578b<\/h3>\n<p data-pid=\"FVYkCHay\">\u8f6f\u4ef6\u5de5\u7a0b\u4e2d\uff0c\u6211\u4eec\u4e0d\u4ec5\u8981\u521b\u5efa\u4e00\u81f4\u7684\u5b9a\u4e49\u826f\u597d\u7684 API\uff0c\u540c\u65f6\u4e5f\u8981\u8003\u8651\u53ef\u91cd\u7528\u6027\u3002 \u7ec4\u4ef6\u4e0d\u4ec5\u80fd\u591f\u652f\u6301\u5f53\u524d\u7684\u6570\u636e\u7c7b\u578b\uff0c\u540c\u65f6\u4e5f\u80fd\u652f\u6301\u672a\u6765\u7684\u6570\u636e\u7c7b\u578b\uff0c\u8fd9\u5728\u521b\u5efa\u5927\u578b\u7cfb\u7edf\u65f6\u4e3a\u4f60\u63d0\u4f9b\u4e86\u5341\u5206\u7075\u6d3b\u7684\u529f\u80fd\u3002<\/p>\n<p data-pid=\"VoMkRsi1\"><b>\u5728\u50cf C# \u548c Java \u8fd9\u6837\u7684\u8bed\u8a00\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u6cdb\u578b\u6765\u521b\u5efa\u53ef\u91cd\u7528\u7684\u7ec4\u4ef6\uff0c\u4e00\u4e2a\u7ec4\u4ef6\u53ef\u4ee5\u652f\u6301\u591a\u79cd\u7c7b\u578b\u7684\u6570\u636e\u3002 \u8fd9\u6837\u7528\u6237\u5c31\u53ef\u4ee5\u4ee5\u81ea\u5df1\u7684\u6570\u636e\u7c7b\u578b\u6765\u4f7f\u7528\u7ec4\u4ef6\u3002<\/b><\/p>\n<p data-pid=\"vs0i-cyS\">\u8bbe\u8ba1\u6cdb\u578b\u7684\u5173\u952e\u76ee\u7684\u662f\u5728\u6210\u5458\u4e4b\u95f4\u63d0\u4f9b\u6709\u610f\u4e49\u7684\u7ea6\u675f\uff0c\u8fd9\u4e9b\u6210\u5458\u53ef\u4ee5\u662f\uff1a\u7c7b\u7684\u5b9e\u4f8b\u6210\u5458\u3001\u7c7b\u7684\u65b9\u6cd5\u3001\u51fd\u6570\u53c2\u6570\u548c\u51fd\u6570\u8fd4\u56de\u503c\u3002<\/p>\n<p data-pid=\"Hr7xPcSW\">\u6cdb\u578b\uff08Generics\uff09\u662f\u5141\u8bb8\u540c\u4e00\u4e2a\u51fd\u6570\u63a5\u53d7\u4e0d\u540c\u7c7b\u578b\u53c2\u6570\u7684\u4e00\u79cd\u6a21\u677f\u3002\u76f8\u6bd4\u4e8e\u4f7f\u7528 any \u7c7b\u578b\uff0c\u4f7f\u7528\u6cdb\u578b\u6765\u521b\u5efa\u53ef\u590d\u7528\u7684\u7ec4\u4ef6\u8981\u66f4\u597d\uff0c\u56e0\u4e3a\u6cdb\u578b\u4f1a\u4fdd\u7559\u53c2\u6570\u7c7b\u578b\u3002<\/p>\n<h3>12.1 \u6cdb\u578b\u63a5\u53e3<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">interface GenericIdentityFn&lt;T&gt; {\r\n  (arg: T): T;\r\n}<\/code><\/pre>\n<\/div>\n<h3>12.2 \u6cdb\u578b\u7c7b<\/h3>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">class GenericNumber&lt;T&gt; {\r\n  zeroValue: T;\r\n  add: (x: T, y: T) =&gt; T;\r\n}\r\n\r\nlet myGenericNumber = new GenericNumber&lt;number&gt;();\r\nmyGenericNumber.zeroValue = 0;\r\nmyGenericNumber.add = function (x, y) {\r\n  return x + y;\r\n};<\/code><\/pre>\n<\/div>\n<h3>12.3 \u6cdb\u578b\u53d8\u91cf<\/h3>\n<p data-pid=\"ELYw7Cn_\">\u5bf9\u521a\u63a5\u89e6 TypeScript \u6cdb\u578b\u7684\u5c0f\u4f19\u4f34\u6765\u8bf4\uff0c\u770b\u5230 T \u548c E\uff0c\u8fd8\u6709 K \u548c V \u8fd9\u4e9b\u6cdb\u578b\u53d8\u91cf\u65f6\uff0c\u4f30\u8ba1\u4f1a\u4e00\u8138\u61f5\u903c\u3002\u5176\u5b9e\u8fd9\u4e9b\u5927\u5199\u5b57\u6bcd\u5e76\u6ca1\u6709\u4ec0\u4e48\u672c\u8d28\u7684\u533a\u522b\uff0c\u53ea\u4e0d\u8fc7\u662f\u4e00\u4e2a\u7ea6\u5b9a\u597d\u7684\u89c4\u8303\u800c\u5df2\u3002\u4e5f\u5c31\u662f\u8bf4\u4f7f\u7528\u5927\u5199\u5b57\u6bcd A-Z \u5b9a\u4e49\u7684\u7c7b\u578b\u53d8\u91cf\u90fd\u5c5e\u4e8e\u6cdb\u578b\uff0c\u628a T \u6362\u6210 A\uff0c\u4e5f\u662f\u4e00\u6837\u7684\u3002\u4e0b\u9762\u6211\u4eec\u4ecb\u7ecd\u4e00\u4e0b\u4e00\u4e9b\u5e38\u89c1\u6cdb\u578b\u53d8\u91cf\u4ee3\u8868\u7684\u610f\u601d\uff1a<\/p>\n<ul>\n<li data-pid=\"pdVo7JEW\">T\uff08Type\uff09\uff1a\u8868\u793a\u4e00\u4e2a TypeScript \u7c7b\u578b<\/li>\n<li data-pid=\"JtWwuHWk\">K\uff08Key\uff09\uff1a\u8868\u793a\u5bf9\u8c61\u4e2d\u7684\u952e\u7c7b\u578b<\/li>\n<li data-pid=\"5misyfIy\">V\uff08Value\uff09\uff1a\u8868\u793a\u5bf9\u8c61\u4e2d\u7684\u503c\u7c7b\u578b<\/li>\n<li data-pid=\"CGUM9SK9\">E\uff08Element\uff09\uff1a\u8868\u793a\u5143\u7d20\u7c7b\u578b<\/li>\n<\/ul>\n<h3>12.4 \u6cdb\u578b\u5de5\u5177\u7c7b\u578b<\/h3>\n<p data-pid=\"J1N_JywO\">\u4e3a\u4e86\u65b9\u4fbf\u5f00\u53d1\u8005 TypeScript \u5185\u7f6e\u4e86\u4e00\u4e9b\u5e38\u7528\u7684\u5de5\u5177\u7c7b\u578b\uff0c\u6bd4\u5982 Partial\u3001Required\u3001Readonly\u3001Record \u548c ReturnType \u7b49\u3002\u51fa\u4e8e\u7bc7\u5e45\u8003\u8651\uff0c\u8fd9\u91cc\u6211\u4eec\u53ea\u7b80\u5355\u4ecb\u7ecd Partial \u5de5\u5177\u7c7b\u578b\u3002\u4e0d\u8fc7\u5728\u5177\u4f53\u4ecb\u7ecd\u4e4b\u524d\uff0c\u6211\u4eec\u5f97\u5148\u4ecb\u7ecd\u4e00\u4e9b\u76f8\u5173\u7684\u57fa\u7840\u77e5\u8bc6\uff0c\u65b9\u4fbf\u8bfb\u8005\u81ea\u884c\u5b66\u4e60\u5176\u5b83\u7684\u5de5\u5177\u7c7b\u578b\u3002<\/p>\n<p data-pid=\"2oaH3LFY\"><b>1.typeof<\/b><\/p>\n<p data-pid=\"Jhdww9WQ\">\u5728 TypeScript \u4e2d\uff0c<code>typeof<\/code>\u00a0\u64cd\u4f5c\u7b26\u53ef\u4ee5\u7528\u6765\u83b7\u53d6\u4e00\u4e2a\u53d8\u91cf\u58f0\u660e\u6216\u5bf9\u8c61\u7684\u7c7b\u578b\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">interface Person {\r\n  name: string;\r\n  age: number;\r\n}\r\n\r\nconst sem: Person = { name: 'semlinker', age: 30 };\r\ntype Sem= typeof sem; \/\/ -&gt; Person\r\n\r\nfunction toArray(x: number): Array&lt;number&gt; {\r\n  return [x];\r\n}\r\n\r\ntype Func = typeof toArray; \/\/ -&gt; (x: number) =&gt; number[]<\/code><\/pre>\n<\/div>\n<p data-pid=\"vvKfsnAC\"><b>2.keyof<\/b><\/p>\n<p data-pid=\"lb8Vytph\"><code>keyof<\/code>\u00a0\u64cd\u4f5c\u7b26\u53ef\u4ee5\u7528\u6765\u4e00\u4e2a\u5bf9\u8c61\u4e2d\u7684\u6240\u6709 key \u503c\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">interface Person {\r\n    name: string;\r\n    age: number;\r\n}\r\n\r\ntype K1 = keyof Person; \/\/ \"name\" | \"age\"\r\ntype K2 = keyof Person[]; \/\/ \"length\" | \"toString\" | \"pop\" | \"push\" | \"concat\" | \"join\" \r\ntype K3 = keyof { [x: string]: Person };  \/\/ string | number<\/code><\/pre>\n<\/div>\n<p data-pid=\"nclbwbR9\"><b><a class=\" external\" href=\"https:\/\/link.zhihu.com\/?target=http%3A\/\/3.in\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\"><span class=\"invisible\">http:\/\/<\/span><span class=\"visible\">3.in<\/span><\/a><\/b><\/p>\n<p data-pid=\"MindDEhk\"><code>in<\/code>\u00a0\u7528\u6765\u904d\u5386\u679a\u4e3e\u7c7b\u578b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">type Keys = \"a\" | \"b\" | \"c\"\r\n\r\ntype Obj =  {\r\n  [p in Keys]: any\r\n} \/\/ -&gt; { a: any, b: any, c: any }<\/code><\/pre>\n<\/div>\n<p data-pid=\"TiqL8NWK\"><b>4.infer<\/b><\/p>\n<p data-pid=\"6RTegW6P\">\u5728\u6761\u4ef6\u7c7b\u578b\u8bed\u53e5\u4e2d\uff0c\u53ef\u4ee5\u7528\u00a0<code>infer<\/code>\u00a0\u58f0\u660e\u4e00\u4e2a\u7c7b\u578b\u53d8\u91cf\u5e76\u4e14\u5bf9\u5b83\u8fdb\u884c\u4f7f\u7528\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">type ReturnType&lt;T&gt; = T extends (\r\n  ...args: any[]\r\n) =&gt; infer R ? R : any;<\/code><\/pre>\n<\/div>\n<p data-pid=\"pZaPt2EV\">\u4ee5\u4e0a\u4ee3\u7801\u4e2d\u00a0<code>infer R<\/code>\u00a0\u5c31\u662f\u58f0\u660e\u4e00\u4e2a\u53d8\u91cf\u6765\u627f\u8f7d\u4f20\u5165\u51fd\u6570\u7b7e\u540d\u7684\u8fd4\u56de\u503c\u7c7b\u578b\uff0c\u7b80\u5355\u8bf4\u5c31\u662f\u7528\u5b83\u53d6\u5230\u51fd\u6570\u8fd4\u56de\u503c\u7684\u7c7b\u578b\u65b9\u4fbf\u4e4b\u540e\u4f7f\u7528\u3002<\/p>\n<p data-pid=\"MPGpeK7e\"><b>5.extends<\/b><\/p>\n<p data-pid=\"E4V187Im\">\u6709\u65f6\u5019\u6211\u4eec\u5b9a\u4e49\u7684\u6cdb\u578b\u4e0d\u60f3\u8fc7\u4e8e\u7075\u6d3b\u6216\u8005\u8bf4\u60f3\u7ee7\u627f\u67d0\u4e9b\u7c7b\u7b49\uff0c\u53ef\u4ee5\u901a\u8fc7 extends \u5173\u952e\u5b57\u6dfb\u52a0\u6cdb\u578b\u7ea6\u675f\u3002<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">interface ILengthwise {\r\n  length: number;\r\n}\r\n\r\nfunction loggingIdentity&lt;T extends ILengthwise&gt;(arg: T): T {\r\n  console.log(arg.length);\r\n  return arg;\r\n}<\/code><\/pre>\n<\/div>\n<p data-pid=\"4x6RUD5l\">\u73b0\u5728\u8fd9\u4e2a\u6cdb\u578b\u51fd\u6570\u88ab\u5b9a\u4e49\u4e86\u7ea6\u675f\uff0c\u56e0\u6b64\u5b83\u4e0d\u518d\u662f\u9002\u7528\u4e8e\u4efb\u610f\u7c7b\u578b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">loggingIdentity(3); \/\/ Error, number doesn't have a .length property<\/code><\/pre>\n<\/div>\n<p data-pid=\"QJxAAXco\">\u8fd9\u65f6\u6211\u4eec\u9700\u8981\u4f20\u5165\u7b26\u5408\u7ea6\u675f\u7c7b\u578b\u7684\u503c\uff0c\u5fc5\u987b\u5305\u542b\u5fc5\u987b\u7684\u5c5e\u6027\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">loggingIdentity({length: 10, value: 3});<\/code><\/pre>\n<\/div>\n<p data-pid=\"AYSFPAKq\"><b>6.Partial<\/b><\/p>\n<p data-pid=\"mkMVDN8G\"><code>Partial&lt;T&gt;<\/code>\u00a0\u7684\u4f5c\u7528\u5c31\u662f\u5c06\u67d0\u4e2a\u7c7b\u578b\u91cc\u7684\u5c5e\u6027\u5168\u90e8\u53d8\u4e3a\u53ef\u9009\u9879\u00a0<code>?<\/code>\u3002<\/p>\n<p data-pid=\"mdMQuVQp\"><b>\u5b9a\u4e49\uff1a<\/b><\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">\/**\r\n * node_modules\/typescript\/lib\/lib.es5.d.ts\r\n * Make all properties in T optional\r\n *\/\r\ntype Partial&lt;T&gt; = {\r\n  [P in keyof T]?: T[P];\r\n};<\/code><\/pre>\n<\/div>\n<p data-pid=\"QSHD7TrU\">\u5728\u4ee5\u4e0a\u4ee3\u7801\u4e2d\uff0c\u9996\u5148\u901a\u8fc7\u00a0<code>keyof T<\/code>\u00a0\u62ff\u5230\u00a0<code>T<\/code>\u00a0\u7684\u6240\u6709\u5c5e\u6027\u540d\uff0c\u7136\u540e\u4f7f\u7528\u00a0<code>in<\/code>\u00a0\u8fdb\u884c\u904d\u5386\uff0c\u5c06\u503c\u8d4b\u7ed9\u00a0<code>P<\/code>\uff0c\u6700\u540e\u901a\u8fc7\u00a0<code>T[P]<\/code>\u00a0\u53d6\u5f97\u76f8\u5e94\u7684\u5c5e\u6027\u503c\u3002\u4e2d\u95f4\u7684\u00a0<code>?<\/code>\u00a0\u53f7\uff0c\u7528\u4e8e\u5c06\u6240\u6709\u5c5e\u6027\u53d8\u4e3a\u53ef\u9009\u3002<\/p>\n<p data-pid=\"OfwZGKFY\"><b>\u793a\u4f8b\uff1a<\/b><\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">interface Todo {\r\n  title: string;\r\n  description: string;\r\n}\r\n\r\nfunction updateTodo(todo: Todo, fieldsToUpdate: Partial&lt;Todo&gt;) {\r\n  return { ...todo, ...fieldsToUpdate };\r\n}\r\n\r\nconst todo1 = {\r\n  title: \"organize desk\",\r\n  description: \"clear clutter\",\r\n};\r\n\r\nconst todo2 = updateTodo(todo1, {\r\n  description: \"throw out trash\",\r\n});<\/code><\/pre>\n<\/div>\n<p data-pid=\"mPoQ18Vg\">\u5728\u4e0a\u9762\u7684\u00a0<code>updateTodo<\/code>\u00a0\u65b9\u6cd5\u4e2d\uff0c\u6211\u4eec\u5229\u7528\u00a0<code>Partial&lt;T&gt;<\/code>\u00a0\u5de5\u5177\u7c7b\u578b\uff0c\u5b9a\u4e49\u00a0<code>fieldsToUpdate<\/code>\u00a0\u7684\u7c7b\u578b\u4e3a\u00a0<code>Partial&lt;Todo&gt;<\/code>\uff0c\u5373\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">{\r\n   title?: string | undefined;\r\n   description?: string | undefined;\r\n}<\/code><\/pre>\n<\/div>\n<h3>\u5341\u4e09\u3001TypeScript \u88c5\u9970\u5668<\/h3>\n<h3>13.1 \u88c5\u9970\u5668\u662f\u4ec0\u4e48<\/h3>\n<ul>\n<li data-pid=\"pIB9-f3h\">\u5b83\u662f\u4e00\u4e2a\u8868\u8fbe\u5f0f<\/li>\n<li data-pid=\"38HxmD6n\">\u8be5\u8868\u8fbe\u5f0f\u88ab\u6267\u884c\u540e\uff0c\u8fd4\u56de\u4e00\u4e2a\u51fd\u6570<\/li>\n<li data-pid=\"ingfRvJ1\">\u51fd\u6570\u7684\u5165\u53c2\u5206\u522b\u4e3a target\u3001name \u548c descriptor<\/li>\n<li data-pid=\"Jo93QQVm\">\u6267\u884c\u8be5\u51fd\u6570\u540e\uff0c\u53ef\u80fd\u8fd4\u56de descriptor \u5bf9\u8c61\uff0c\u7528\u4e8e\u914d\u7f6e target \u5bf9\u8c61<\/li>\n<\/ul>\n<h3>13.2 \u88c5\u9970\u5668\u7684\u5206\u7c7b<\/h3>\n<ul>\n<li data-pid=\"PwTea19M\">\u7c7b\u88c5\u9970\u5668\uff08Class decorators\uff09<\/li>\n<li data-pid=\"KRn5bZby\">\u5c5e\u6027\u88c5\u9970\u5668\uff08Property decorators\uff09<\/li>\n<li data-pid=\"oMPl9fAH\">\u65b9\u6cd5\u88c5\u9970\u5668\uff08Method decorators\uff09<\/li>\n<li data-pid=\"vymBz3Pk\">\u53c2\u6570\u88c5\u9970\u5668\uff08Parameter decorators\uff09<\/li>\n<\/ul>\n<h3>13.3 \u7c7b\u88c5\u9970\u5668<\/h3>\n<p data-pid=\"z0RU90A_\">\u7c7b\u88c5\u9970\u5668\u58f0\u660e\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">declare type ClassDecorator = &lt;TFunction extends Function&gt;(\r\n  target: TFunction\r\n) =&gt; TFunction | void;<\/code><\/pre>\n<\/div>\n<p data-pid=\"WBioNhc3\">\u7c7b\u88c5\u9970\u5668\u987e\u540d\u601d\u4e49\uff0c\u5c31\u662f\u7528\u6765\u88c5\u9970\u7c7b\u7684\u3002\u5b83\u63a5\u6536\u4e00\u4e2a\u53c2\u6570\uff1a<\/p>\n<ul>\n<li data-pid=\"51aMAvla\">target: TFunction &#8211; \u88ab\u88c5\u9970\u7684\u7c7b<\/li>\n<\/ul>\n<p data-pid=\"-v-j0u5L\">\u770b\u5b8c\u7b2c\u4e00\u773c\u540e\uff0c\u662f\u4e0d\u662f\u611f\u89c9\u90fd\u4e0d\u597d\u4e86\u3002\u6ca1\u4e8b\uff0c\u6211\u4eec\u9a6c\u4e0a\u6765\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">function Greeter(target: Function): void {\r\n  target.prototype.greet = function (): void {\r\n    console.log(\"Hello Semlinker!\");\r\n  };\r\n}\r\n\r\n@Greeter\r\nclass Greeting {\r\n  constructor() {\r\n    \/\/ \u5185\u90e8\u5b9e\u73b0\r\n  }\r\n}\r\n\r\nlet myGreeting = new Greeting();\r\nmyGreeting.greet(); \/\/ console output: 'Hello Semlinker!';<\/code><\/pre>\n<\/div>\n<p data-pid=\"xHTpKq7q\">\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u5b9a\u4e49\u4e86\u00a0<code>Greeter<\/code>\u00a0\u7c7b\u88c5\u9970\u5668\uff0c\u540c\u65f6\u6211\u4eec\u4f7f\u7528\u4e86\u00a0<code>@Greeter<\/code>\u00a0\u8bed\u6cd5\u7cd6\uff0c\u6765\u4f7f\u7528\u88c5\u9970\u5668\u3002<\/p>\n<blockquote data-pid=\"rYyk-PVC\"><p>\u53cb\u60c5\u63d0\u793a\uff1a\u8bfb\u8005\u53ef\u4ee5\u76f4\u63a5\u590d\u5236\u4e0a\u9762\u7684\u4ee3\u7801\uff0c\u5728\u00a0<a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=https%3A\/\/www.typescriptlang.org\/play\/index.html\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">TypeScript Playground<\/a>\u00a0\u4e2d\u8fd0\u884c\u67e5\u770b\u7ed3\u679c\u3002<\/p><\/blockquote>\n<p data-pid=\"KKcHTykS\">\u6709\u7684\u8bfb\u8005\u53ef\u80fd\u60f3\u95ee\uff0c\u4f8b\u5b50\u4e2d\u603b\u662f\u8f93\u51fa\u00a0<code>Hello Semlinker!<\/code>\u00a0\uff0c\u80fd\u81ea\u5b9a\u4e49\u8f93\u51fa\u7684\u95ee\u5019\u8bed\u4e48 \uff1f\u8fd9\u4e2a\u95ee\u9898\u5f88\u597d\uff0c\u7b54\u6848\u662f\u53ef\u4ee5\u7684\u3002<\/p>\n<p data-pid=\"UfTazFPv\">\u5177\u4f53\u5b9e\u73b0\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">function Greeter(greeting: string) {\r\n  return function (target: Function) {\r\n    target.prototype.greet = function (): void {\r\n      console.log(greeting);\r\n    };\r\n  };\r\n}\r\n\r\n@Greeter(\"Hello TS!\")\r\nclass Greeting {\r\n  constructor() {\r\n    \/\/ \u5185\u90e8\u5b9e\u73b0\r\n  }\r\n}\r\n\r\nlet myGreeting = new Greeting();\r\nmyGreeting.greet(); \/\/ console output: 'Hello TS!';<\/code><\/pre>\n<\/div>\n<h3>13.4 \u5c5e\u6027\u88c5\u9970\u5668<\/h3>\n<p data-pid=\"waGFBLFL\">\u5c5e\u6027\u88c5\u9970\u5668\u58f0\u660e\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">declare type PropertyDecorator = (target:Object, \r\n  propertyKey: string | symbol ) =&gt; void;<\/code><\/pre>\n<\/div>\n<p data-pid=\"xy7tuS3b\">\u5c5e\u6027\u88c5\u9970\u5668\u987e\u540d\u601d\u4e49\uff0c\u7528\u6765\u88c5\u9970\u7c7b\u7684\u5c5e\u6027\u3002\u5b83\u63a5\u6536\u4e24\u4e2a\u53c2\u6570\uff1a<\/p>\n<ul>\n<li data-pid=\"6Qz7Lmsy\">target: Object &#8211; \u88ab\u88c5\u9970\u7684\u7c7b<\/li>\n<li data-pid=\"gij5we_O\">propertyKey: string | symbol &#8211; \u88ab\u88c5\u9970\u7c7b\u7684\u5c5e\u6027\u540d<\/li>\n<\/ul>\n<p data-pid=\"c50_UogC\">\u8d81\u70ed\u6253\u94c1\uff0c\u9a6c\u4e0a\u6765\u4e2a\u4f8b\u5b50\u70ed\u70ed\u8eab\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">function logProperty(target: any, key: string) {\r\n  delete target[key];\r\n\r\n  const backingField = \"_\" + key;\r\n\r\n  Object.defineProperty(target, backingField, {\r\n    writable: true,\r\n    enumerable: true,\r\n    configurable: true\r\n  });\r\n\r\n  \/\/ property getter\r\n  const getter = function (this: any) {\r\n    const currVal = this[backingField];\r\n    console.log(`Get: ${key} =&gt; ${currVal}`);\r\n    return currVal;\r\n  };\r\n\r\n  \/\/ property setter\r\n  const setter = function (this: any, newVal: any) {\r\n    console.log(`Set: ${key} =&gt; ${newVal}`);\r\n    this[backingField] = newVal;\r\n  };\r\n\r\n  \/\/ Create new property with getter and setter\r\n  Object.defineProperty(target, key, {\r\n    get: getter,\r\n    set: setter,\r\n    enumerable: true,\r\n    configurable: true\r\n  });\r\n}\r\n\r\nclass Person { \r\n  @logProperty\r\n  public name: string;\r\n\r\n  constructor(name : string) { \r\n    this.name = name;\r\n  }\r\n}\r\n\r\nconst p1 = new Person(\"semlinker\");\r\np1.name = \"kakuqo\";<\/code><\/pre>\n<\/div>\n<p data-pid=\"QsHlddAm\">\u4ee5\u4e0a\u4ee3\u7801\u6211\u4eec\u5b9a\u4e49\u4e86\u4e00\u4e2a\u00a0<code>logProperty<\/code>\u00a0\u51fd\u6570\uff0c\u6765\u8ddf\u8e2a\u7528\u6237\u5bf9\u5c5e\u6027\u7684\u64cd\u4f5c\uff0c\u5f53\u4ee3\u7801\u6210\u529f\u8fd0\u884c\u540e\uff0c\u5728\u63a7\u5236\u53f0\u4f1a\u8f93\u51fa\u4ee5\u4e0b\u7ed3\u679c\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">Set: name =&gt; semlinker\r\nSet: name =&gt; kakuqo<\/code><\/pre>\n<\/div>\n<h3>13.5 \u65b9\u6cd5\u88c5\u9970\u5668<\/h3>\n<p data-pid=\"9pqNgcUs\">\u65b9\u6cd5\u88c5\u9970\u5668\u58f0\u660e\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">declare type MethodDecorator = &lt;T&gt;(target:Object, propertyKey: string | symbol,          \r\n  descriptor: TypePropertyDescript&lt;T&gt;) =&gt; TypedPropertyDescriptor&lt;T&gt; | void;<\/code><\/pre>\n<\/div>\n<p data-pid=\"94tDpaGP\">\u65b9\u6cd5\u88c5\u9970\u5668\u987e\u540d\u601d\u4e49\uff0c\u7528\u6765\u88c5\u9970\u7c7b\u7684\u65b9\u6cd5\u3002\u5b83\u63a5\u6536\u4e09\u4e2a\u53c2\u6570\uff1a<\/p>\n<ul>\n<li data-pid=\"NaTVHDaQ\">target: Object &#8211; \u88ab\u88c5\u9970\u7684\u7c7b<\/li>\n<li data-pid=\"2JPzsUzg\">propertyKey: string | symbol &#8211; \u65b9\u6cd5\u540d<\/li>\n<li data-pid=\"zgvf2V8t\">descriptor: TypePropertyDescript &#8211; \u5c5e\u6027\u63cf\u8ff0\u7b26<\/li>\n<\/ul>\n<p data-pid=\"6vecqfbi\">\u5e9f\u8bdd\u4e0d\u591a\u8bf4\uff0c\u76f4\u63a5\u4e0a\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">function LogOutput(tarage: Function, key: string, descriptor: any) {\r\n  let originalMethod = descriptor.value;\r\n  let newMethod = function(...args: any[]): any {\r\n    let result: any = originalMethod.apply(this, args);\r\n    if(!this.loggedOutput) {\r\n      this.loggedOutput = new Array&lt;any&gt;();\r\n    }\r\n    this.loggedOutput.push({\r\n      method: key,\r\n      parameters: args,\r\n      output: result,\r\n      timestamp: new Date()\r\n    });\r\n    return result;\r\n  };\r\n  descriptor.value = newMethod;\r\n}\r\n\r\nclass Calculator {\r\n  @LogOutput\r\n  double (num: number): number {\r\n    return num * 2;\r\n  }\r\n}\r\n\r\nlet calc = new Calculator();\r\ncalc.double(11);\r\n\/\/ console ouput: [{method: \"double\", output: 22, ...}]\r\nconsole.log(calc.loggedOutput);<\/code><\/pre>\n<\/div>\n<p data-pid=\"HYneMWlc\">\u4e0b\u9762\u6211\u4eec\u6765\u4ecb\u7ecd\u4e00\u4e0b\u53c2\u6570\u88c5\u9970\u5668\u3002<\/p>\n<h3>13.6 \u53c2\u6570\u88c5\u9970\u5668<\/h3>\n<p data-pid=\"4MUS2OML\">\u53c2\u6570\u88c5\u9970\u5668\u58f0\u660e\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">declare type ParameterDecorator = (target: Object, propertyKey: string | symbol, \r\n  parameterIndex: number ) =&gt; void<\/code><\/pre>\n<\/div>\n<p data-pid=\"Y6XjEUxs\">\u53c2\u6570\u88c5\u9970\u5668\u987e\u540d\u601d\u4e49\uff0c\u662f\u7528\u6765\u88c5\u9970\u51fd\u6570\u53c2\u6570\uff0c\u5b83\u63a5\u6536\u4e09\u4e2a\u53c2\u6570\uff1a<\/p>\n<ul>\n<li data-pid=\"5ubBbpV5\">target: Object &#8211; \u88ab\u88c5\u9970\u7684\u7c7b<\/li>\n<li data-pid=\"fgHVi9AR\">propertyKey: string | symbol &#8211; \u65b9\u6cd5\u540d<\/li>\n<li data-pid=\"81W17gvy\">parameterIndex: number &#8211; \u65b9\u6cd5\u4e2d\u53c2\u6570\u7684\u7d22\u5f15\u503c<\/li>\n<\/ul>\n<div class=\"highlight\">\n<pre><code class=\"language-text\">function Log(target: Function, key: string, parameterIndex: number) {\r\n  let functionLogged = key || target.prototype.constructor.name;\r\n  console.log(`The parameter in position ${parameterIndex} at ${functionLogged} has\r\n    been decorated`);\r\n}\r\n\r\nclass Greeter {\r\n  greeting: string;\r\n  constructor(@Log phrase: string) {\r\n    this.greeting = phrase; \r\n  }\r\n}\r\n\r\n\/\/ console output: The parameter in position 0 \r\n\/\/ at Greeter has been decorated<\/code><\/pre>\n<\/div>\n<p data-pid=\"nlQOxtvp\">\u4ecb\u7ecd\u5b8c TypeScript \u5165\u95e8\u76f8\u5173\u7684\u57fa\u7840\u77e5\u8bc6\uff0c\u731c\u6d4b\u5f88\u591a\u521a\u5165\u95e8\u7684\u5c0f\u4f19\u4f34\u5df2\u6709\u00a0<b>\u201c\u4ece\u5165\u95e8\u5230\u653e\u5f03\u201d<\/b>\u00a0\u7684\u60f3\u6cd5\uff0c\u6700\u540e\u6211\u4eec\u6765\u7b80\u5355\u4ecb\u7ecd\u4e00\u4e0b\u7f16\u8bd1\u4e0a\u4e0b\u6587\u3002<\/p>\n<h3>\u5341\u56db\u3001\u7f16\u8bd1\u4e0a\u4e0b\u6587<\/h3>\n<h3>14.1 tsconfig.json \u7684\u4f5c\u7528<\/h3>\n<ul>\n<li data-pid=\"xvqq34Qo\">\u7528\u4e8e\u6807\u8bc6 TypeScript \u9879\u76ee\u7684\u6839\u8def\u5f84\uff1b<\/li>\n<li data-pid=\"wBxTQEU9\">\u7528\u4e8e\u914d\u7f6e TypeScript \u7f16\u8bd1\u5668\uff1b<\/li>\n<li data-pid=\"_mTGNnR5\">\u7528\u4e8e\u6307\u5b9a\u7f16\u8bd1\u7684\u6587\u4ef6\u3002<\/li>\n<\/ul>\n<h3>14.2 tsconfig.json \u91cd\u8981\u5b57\u6bb5<\/h3>\n<ul>\n<li data-pid=\"vvwEUJji\">files &#8211; \u8bbe\u7f6e\u8981\u7f16\u8bd1\u7684\u6587\u4ef6\u7684\u540d\u79f0\uff1b<\/li>\n<li data-pid=\"fDWvrQUK\">include &#8211; \u8bbe\u7f6e\u9700\u8981\u8fdb\u884c\u7f16\u8bd1\u7684\u6587\u4ef6\uff0c\u652f\u6301\u8def\u5f84\u6a21\u5f0f\u5339\u914d\uff1b<\/li>\n<li data-pid=\"-FEHQe0M\">exclude &#8211; \u8bbe\u7f6e\u65e0\u9700\u8fdb\u884c\u7f16\u8bd1\u7684\u6587\u4ef6\uff0c\u652f\u6301\u8def\u5f84\u6a21\u5f0f\u5339\u914d\uff1b<\/li>\n<li data-pid=\"cIIae01N\">compilerOptions &#8211; \u8bbe\u7f6e\u4e0e\u7f16\u8bd1\u6d41\u7a0b\u76f8\u5173\u7684\u9009\u9879\u3002<\/li>\n<\/ul>\n<h3>14.3 compilerOptions \u9009\u9879<\/h3>\n<p data-pid=\"9hjWQt8c\">compilerOptions \u652f\u6301\u5f88\u591a\u9009\u9879\uff0c\u5e38\u89c1\u7684\u6709\u00a0<code>baseUrl<\/code>\u3001\u00a0<code>target<\/code>\u3001<code>baseUrl<\/code>\u3001\u00a0<code>moduleResolution<\/code>\u00a0\u548c\u00a0<code>lib<\/code>\u00a0\u7b49\u3002<\/p>\n<p data-pid=\"juvsBAaI\">compilerOptions \u6bcf\u4e2a\u9009\u9879\u7684\u8be6\u7ec6\u8bf4\u660e\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight\">\n<pre><code class=\"language-json\"><span class=\"p\">{<\/span>\r\n  <span class=\"nt\">\"compilerOptions\"<\/span><span class=\"p\">:<\/span> <span class=\"p\">{<\/span>\r\n\r\n    <span class=\"err\">\/*<\/span> <span class=\"err\">\u57fa\u672c\u9009\u9879<\/span> <span class=\"err\">*\/<\/span>\r\n    <span class=\"nt\">\"target\"<\/span><span class=\"p\">:<\/span> <span class=\"s2\">\"es5\"<\/span><span class=\"p\">,<\/span>                       <span class=\"err\">\/\/<\/span> <span class=\"err\">\u6307\u5b9a<\/span> <span class=\"err\">ECMAScript<\/span> <span class=\"err\">\u76ee\u6807\u7248\u672c:<\/span> <span class=\"err\">'ES3'<\/span> <span class=\"err\">(default),<\/span> <span class=\"err\">'ES5',<\/span> <span class=\"err\">'ES6'\/'ES2015',<\/span> <span class=\"err\">'ES2016',<\/span> <span class=\"err\">'ES2017',<\/span> <span class=\"err\">or<\/span> <span class=\"err\">'ESNEXT'<\/span>\r\n    <span class=\"nt\">\"module\"<\/span><span class=\"p\">:<\/span> <span class=\"s2\">\"commonjs\"<\/span><span class=\"p\">,<\/span>                  <span class=\"err\">\/\/<\/span> <span class=\"err\">\u6307\u5b9a\u4f7f\u7528\u6a21\u5757:<\/span> <span class=\"err\">'commonjs',<\/span> <span class=\"err\">'amd',<\/span> <span class=\"err\">'system',<\/span> <span class=\"err\">'umd'<\/span> <span class=\"err\">or<\/span> <span class=\"err\">'es2015'<\/span>\r\n    <span class=\"nt\">\"lib\"<\/span><span class=\"p\">:<\/span> <span class=\"p\">[],<\/span>                             <span class=\"err\">\/\/<\/span> <span class=\"err\">\u6307\u5b9a\u8981\u5305\u542b\u5728\u7f16\u8bd1\u4e2d\u7684\u5e93\u6587\u4ef6<\/span>\r\n    <span class=\"nt\">\"allowJs\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                       <span class=\"err\">\/\/<\/span> <span class=\"err\">\u5141\u8bb8\u7f16\u8bd1<\/span> <span class=\"err\">javascript<\/span> <span class=\"err\">\u6587\u4ef6<\/span>\r\n    <span class=\"nt\">\"checkJs\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                       <span class=\"err\">\/\/<\/span> <span class=\"err\">\u62a5\u544a<\/span> <span class=\"err\">javascript<\/span> <span class=\"err\">\u6587\u4ef6\u4e2d\u7684\u9519\u8bef<\/span>\r\n    <span class=\"nt\">\"jsx\"<\/span><span class=\"p\">:<\/span> <span class=\"s2\">\"preserve\"<\/span><span class=\"p\">,<\/span>                     <span class=\"err\">\/\/<\/span> <span class=\"err\">\u6307\u5b9a<\/span> <span class=\"err\">jsx<\/span> <span class=\"err\">\u4ee3\u7801\u7684\u751f\u6210:<\/span> <span class=\"err\">'preserve',<\/span> <span class=\"err\">'react-native',<\/span> <span class=\"err\">or<\/span> <span class=\"err\">'react'<\/span>\r\n    <span class=\"nt\">\"declaration\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                   <span class=\"err\">\/\/<\/span> <span class=\"err\">\u751f\u6210\u76f8\u5e94\u7684<\/span> <span class=\"err\">'.d.ts'<\/span> <span class=\"err\">\u6587\u4ef6<\/span>\r\n    <span class=\"nt\">\"sourceMap\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                     <span class=\"err\">\/\/<\/span> <span class=\"err\">\u751f\u6210\u76f8\u5e94\u7684<\/span> <span class=\"err\">'.map'<\/span> <span class=\"err\">\u6587\u4ef6<\/span>\r\n    <span class=\"nt\">\"outFile\"<\/span><span class=\"p\">:<\/span> <span class=\"s2\">\".\/\"<\/span><span class=\"p\">,<\/span>                       <span class=\"err\">\/\/<\/span> <span class=\"err\">\u5c06\u8f93\u51fa\u6587\u4ef6\u5408\u5e76\u4e3a\u4e00\u4e2a\u6587\u4ef6<\/span>\r\n    <span class=\"nt\">\"outDir\"<\/span><span class=\"p\">:<\/span> <span class=\"s2\">\".\/\"<\/span><span class=\"p\">,<\/span>                        <span class=\"err\">\/\/<\/span> <span class=\"err\">\u6307\u5b9a\u8f93\u51fa\u76ee\u5f55<\/span>\r\n    <span class=\"nt\">\"rootDir\"<\/span><span class=\"p\">:<\/span> <span class=\"s2\">\".\/\"<\/span><span class=\"p\">,<\/span>                       <span class=\"err\">\/\/<\/span> <span class=\"err\">\u7528\u6765\u63a7\u5236\u8f93\u51fa\u76ee\u5f55\u7ed3\u6784<\/span> <span class=\"err\">--outDir.<\/span>\r\n    <span class=\"nt\">\"removeComments\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                <span class=\"err\">\/\/<\/span> <span class=\"err\">\u5220\u9664\u7f16\u8bd1\u540e\u7684\u6240\u6709\u7684\u6ce8\u91ca<\/span>\r\n    <span class=\"nt\">\"noEmit\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                        <span class=\"err\">\/\/<\/span> <span class=\"err\">\u4e0d\u751f\u6210\u8f93\u51fa\u6587\u4ef6<\/span>\r\n    <span class=\"nt\">\"importHelpers\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                 <span class=\"err\">\/\/<\/span> <span class=\"err\">\u4ece<\/span> <span class=\"err\">tslib<\/span> <span class=\"err\">\u5bfc\u5165\u8f85\u52a9\u5de5\u5177\u51fd\u6570<\/span>\r\n    <span class=\"nt\">\"isolatedModules\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>               <span class=\"err\">\/\/<\/span> <span class=\"err\">\u5c06\u6bcf\u4e2a\u6587\u4ef6\u505a\u4e3a\u5355\u72ec\u7684\u6a21\u5757<\/span> <span class=\"err\">\uff08\u4e0e<\/span> <span class=\"err\">'ts.transpileModule'<\/span> <span class=\"err\">\u7c7b\u4f3c\uff09.<\/span>\r\n\r\n    <span class=\"err\">\/*<\/span> <span class=\"err\">\u4e25\u683c\u7684\u7c7b\u578b\u68c0\u67e5\u9009\u9879<\/span> <span class=\"err\">*\/<\/span>\r\n    <span class=\"nt\">\"strict\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                        <span class=\"err\">\/\/<\/span> <span class=\"err\">\u542f\u7528\u6240\u6709\u4e25\u683c\u7c7b\u578b\u68c0\u67e5\u9009\u9879<\/span>\r\n    <span class=\"nt\">\"noImplicitAny\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                 <span class=\"err\">\/\/<\/span> <span class=\"err\">\u5728\u8868\u8fbe\u5f0f\u548c\u58f0\u660e\u4e0a\u6709\u9690\u542b\u7684<\/span> <span class=\"err\">any\u7c7b\u578b\u65f6\u62a5\u9519<\/span>\r\n    <span class=\"nt\">\"strictNullChecks\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>              <span class=\"err\">\/\/<\/span> <span class=\"err\">\u542f\u7528\u4e25\u683c\u7684<\/span> <span class=\"err\">null<\/span> <span class=\"err\">\u68c0\u67e5<\/span>\r\n    <span class=\"nt\">\"noImplicitThis\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                <span class=\"err\">\/\/<\/span> <span class=\"err\">\u5f53<\/span> <span class=\"err\">this<\/span> <span class=\"err\">\u8868\u8fbe\u5f0f\u503c\u4e3a<\/span> <span class=\"err\">any<\/span> <span class=\"err\">\u7c7b\u578b\u7684\u65f6\u5019\uff0c\u751f\u6210\u4e00\u4e2a\u9519\u8bef<\/span>\r\n    <span class=\"nt\">\"alwaysStrict\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                  <span class=\"err\">\/\/<\/span> <span class=\"err\">\u4ee5\u4e25\u683c\u6a21\u5f0f\u68c0\u67e5\u6bcf\u4e2a\u6a21\u5757\uff0c\u5e76\u5728\u6bcf\u4e2a\u6587\u4ef6\u91cc\u52a0\u5165<\/span> <span class=\"err\">'use<\/span> <span class=\"err\">strict'<\/span>\r\n\r\n    <span class=\"err\">\/*<\/span> <span class=\"err\">\u989d\u5916\u7684\u68c0\u67e5<\/span> <span class=\"err\">*\/<\/span>\r\n    <span class=\"nt\">\"noUnusedLocals\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                <span class=\"err\">\/\/<\/span> <span class=\"err\">\u6709\u672a\u4f7f\u7528\u7684\u53d8\u91cf\u65f6\uff0c\u629b\u51fa\u9519\u8bef<\/span>\r\n    <span class=\"nt\">\"noUnusedParameters\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>            <span class=\"err\">\/\/<\/span> <span class=\"err\">\u6709\u672a\u4f7f\u7528\u7684\u53c2\u6570\u65f6\uff0c\u629b\u51fa\u9519\u8bef<\/span>\r\n    <span class=\"nt\">\"noImplicitReturns\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>             <span class=\"err\">\/\/<\/span> <span class=\"err\">\u5e76\u4e0d\u662f\u6240\u6709\u51fd\u6570\u91cc\u7684\u4ee3\u7801\u90fd\u6709\u8fd4\u56de\u503c\u65f6\uff0c\u629b\u51fa\u9519\u8bef<\/span>\r\n    <span class=\"nt\">\"noFallthroughCasesInSwitch\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>    <span class=\"err\">\/\/<\/span> <span class=\"err\">\u62a5\u544a<\/span> <span class=\"err\">switch<\/span> <span class=\"err\">\u8bed\u53e5\u7684<\/span> <span class=\"err\">fallthrough<\/span> <span class=\"err\">\u9519\u8bef\u3002\uff08\u5373\uff0c\u4e0d\u5141\u8bb8<\/span> <span class=\"err\">switch<\/span> <span class=\"err\">\u7684<\/span> <span class=\"err\">case<\/span> <span class=\"err\">\u8bed\u53e5\u8d2f\u7a7f\uff09<\/span>\r\n\r\n    <span class=\"err\">\/*<\/span> <span class=\"err\">\u6a21\u5757\u89e3\u6790\u9009\u9879<\/span> <span class=\"err\">*\/<\/span>\r\n    <span class=\"nt\">\"moduleResolution\"<\/span><span class=\"p\">:<\/span> <span class=\"s2\">\"node\"<\/span><span class=\"p\">,<\/span>            <span class=\"err\">\/\/<\/span> <span class=\"err\">\u9009\u62e9\u6a21\u5757\u89e3\u6790\u7b56\u7565\uff1a<\/span> <span class=\"err\">'node'<\/span> <span class=\"err\">(Node.js)<\/span> <span class=\"err\">or<\/span> <span class=\"err\">'classic'<\/span> <span class=\"err\">(TypeScript<\/span> <span class=\"err\">pre-1.6)<\/span>\r\n    <span class=\"nt\">\"baseUrl\"<\/span><span class=\"p\">:<\/span> <span class=\"s2\">\".\/\"<\/span><span class=\"p\">,<\/span>                       <span class=\"err\">\/\/<\/span> <span class=\"err\">\u7528\u4e8e\u89e3\u6790\u975e\u76f8\u5bf9\u6a21\u5757\u540d\u79f0\u7684\u57fa\u76ee\u5f55<\/span>\r\n    <span class=\"nt\">\"paths\"<\/span><span class=\"p\">:<\/span> <span class=\"p\">{},<\/span>                           <span class=\"err\">\/\/<\/span> <span class=\"err\">\u6a21\u5757\u540d\u5230\u57fa\u4e8e<\/span> <span class=\"err\">baseUrl<\/span> <span class=\"err\">\u7684\u8def\u5f84\u6620\u5c04\u7684\u5217\u8868<\/span>\r\n    <span class=\"nt\">\"rootDirs\"<\/span><span class=\"p\">:<\/span> <span class=\"p\">[],<\/span>                        <span class=\"err\">\/\/<\/span> <span class=\"err\">\u6839\u6587\u4ef6\u5939\u5217\u8868\uff0c\u5176\u7ec4\u5408\u5185\u5bb9\u8868\u793a\u9879\u76ee\u8fd0\u884c\u65f6\u7684\u7ed3\u6784\u5185\u5bb9<\/span>\r\n    <span class=\"nt\">\"typeRoots\"<\/span><span class=\"p\">:<\/span> <span class=\"p\">[],<\/span>                       <span class=\"err\">\/\/<\/span> <span class=\"err\">\u5305\u542b\u7c7b\u578b\u58f0\u660e\u7684\u6587\u4ef6\u5217\u8868<\/span>\r\n    <span class=\"nt\">\"types\"<\/span><span class=\"p\">:<\/span> <span class=\"p\">[],<\/span>                           <span class=\"err\">\/\/<\/span> <span class=\"err\">\u9700\u8981\u5305\u542b\u7684\u7c7b\u578b\u58f0\u660e\u6587\u4ef6\u540d\u5217\u8868<\/span>\r\n    <span class=\"nt\">\"allowSyntheticDefaultImports\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>  <span class=\"err\">\/\/<\/span> <span class=\"err\">\u5141\u8bb8\u4ece\u6ca1\u6709\u8bbe\u7f6e\u9ed8\u8ba4\u5bfc\u51fa\u7684\u6a21\u5757\u4e2d\u9ed8\u8ba4\u5bfc\u5165\u3002<\/span>\r\n\r\n    <span class=\"err\">\/*<\/span> <span class=\"err\">Source<\/span> <span class=\"err\">Map<\/span> <span class=\"err\">Options<\/span> <span class=\"err\">*\/<\/span>\r\n    <span class=\"nt\">\"sourceRoot\"<\/span><span class=\"p\">:<\/span> <span class=\"s2\">\".\/\"<\/span><span class=\"p\">,<\/span>                    <span class=\"err\">\/\/<\/span> <span class=\"err\">\u6307\u5b9a\u8c03\u8bd5\u5668\u5e94\u8be5\u627e\u5230<\/span> <span class=\"err\">TypeScript<\/span> <span class=\"err\">\u6587\u4ef6\u800c\u4e0d\u662f\u6e90\u6587\u4ef6\u7684\u4f4d\u7f6e<\/span>\r\n    <span class=\"nt\">\"mapRoot\"<\/span><span class=\"p\">:<\/span> <span class=\"s2\">\".\/\"<\/span><span class=\"p\">,<\/span>                       <span class=\"err\">\/\/<\/span> <span class=\"err\">\u6307\u5b9a\u8c03\u8bd5\u5668\u5e94\u8be5\u627e\u5230\u6620\u5c04\u6587\u4ef6\u800c\u4e0d\u662f\u751f\u6210\u6587\u4ef6\u7684\u4f4d\u7f6e<\/span>\r\n    <span class=\"nt\">\"inlineSourceMap\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>               <span class=\"err\">\/\/<\/span> <span class=\"err\">\u751f\u6210\u5355\u4e2a<\/span> <span class=\"err\">soucemaps<\/span> <span class=\"err\">\u6587\u4ef6\uff0c\u800c\u4e0d\u662f\u5c06<\/span> <span class=\"err\">sourcemaps<\/span> <span class=\"err\">\u751f\u6210\u4e0d\u540c\u7684\u6587\u4ef6<\/span>\r\n    <span class=\"nt\">\"inlineSources\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>                 <span class=\"err\">\/\/<\/span> <span class=\"err\">\u5c06\u4ee3\u7801\u4e0e<\/span> <span class=\"err\">sourcemaps<\/span> <span class=\"err\">\u751f\u6210\u5230\u4e00\u4e2a\u6587\u4ef6\u4e2d\uff0c\u8981\u6c42\u540c\u65f6\u8bbe\u7f6e\u4e86<\/span> <span class=\"err\">--inlineSourceMap<\/span> <span class=\"err\">\u6216<\/span> <span class=\"err\">--sourceMap<\/span> <span class=\"err\">\u5c5e\u6027<\/span>\r\n\r\n    <span class=\"err\">\/*<\/span> <span class=\"err\">\u5176\u4ed6\u9009\u9879<\/span> <span class=\"err\">*\/<\/span>\r\n    <span class=\"nt\">\"experimentalDecorators\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span><span class=\"p\">,<\/span>        <span class=\"err\">\/\/<\/span> <span class=\"err\">\u542f\u7528\u88c5\u9970\u5668<\/span>\r\n    <span class=\"nt\">\"emitDecoratorMetadata\"<\/span><span class=\"p\">:<\/span> <span class=\"kc\">true<\/span>          <span class=\"err\">\/\/<\/span> <span class=\"err\">\u4e3a\u88c5\u9970\u5668\u63d0\u4f9b\u5143\u6570\u636e\u7684\u652f\u6301<\/span>\r\n  <span class=\"p\">}<\/span>\r\n<span class=\"p\">}<\/span><\/code><\/pre>\n<\/div>\n<p data-pid=\"nwZuH4wP\">\u770b\u5230\u8fd9\u91cc\u7684\u8bfb\u8005\u90fd\u662f\u201c\u771f\u7231\u201d\uff0c\u5982\u679c\u4f60\u8fd8\u610f\u72b9\u672a\u5c3d\uff0c\u90a3\u5c31\u6765\u770b\u770b\u672c\u4eba\u6574\u7406\u7684 Github \u4e0a 1.5K+ \u7684\u5f00\u6e90\u9879\u76ee\uff1a<a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=https%3A\/\/github.com\/semlinker\/awesome-typescript\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">awesome-typescript<\/a>\u3002<\/p>\n<blockquote data-pid=\"e_yn7jF7\"><p><a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=https%3A\/\/github.com\/semlinker\/awesome-typescript\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">https:\/\/github.com\/semlinker\/&#8230;<\/a><\/p><\/blockquote>\n<h3>\u5341\u4e94\u3001\u53c2\u8003\u8d44\u6e90<\/h3>\n<ul>\n<li data-pid=\"hFmaOnOD\"><a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=https%3A\/\/mariusschulz.com\/blog\/the-unknown-type-in-typescript\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">mariusschulz &#8211; the-unknown-type-in-typescript<\/a><\/li>\n<li data-pid=\"vdzbf6U3\"><a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=https%3A\/\/jkchao.github.io\/typescript-book-chinese\/project\/compilationContext.html%23tsconfig-json\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">\u6df1\u5165\u7406\u89e3 TypeScript &#8211; \u7f16\u8bd1\u4e0a\u4e0b\u6587<\/a><\/li>\n<\/ul>\n<h3>\u5341\u516d\u3001\u63a8\u8350\u9605\u8bfb<\/h3>\n<ul>\n<li data-pid=\"mKFGN23e\"><a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=http%3A\/\/www.semlinker.com\/master-ts-generic\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">\u4e00\u6587\u8bfb\u61c2 TypeScript \u6cdb\u578b\u53ca\u5e94\u7528<\/a><\/li>\n<li data-pid=\"xmNCYNpt\"><a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=http%3A\/\/www.semlinker.com\/deno-quickstart\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">\u4e86\u4e0d\u8d77\u7684 Deno \u5165\u95e8\u7bc7<\/a><\/li>\n<li data-pid=\"sSy9n1NB\"><a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=http%3A\/\/www.semlinker.com\/deno-in-action\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">\u4e86\u4e0d\u8d77\u7684 Deno \u5b9e\u6218\u6559\u7a0b<\/a><\/li>\n<li data-pid=\"dCZueHqS\"><a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=http%3A\/\/www.semlinker.com\/you-dont-know-blob\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">\u4f60\u4e0d\u77e5\u9053\u7684 Blob<\/a><\/li>\n<li data-pid=\"0zzG-9cq\"><a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=http%3A\/\/www.semlinker.com\/you-dont-know-weakmap\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">\u4f60\u4e0d\u77e5\u9053\u7684 WeakMap | \u5168\u6808\u4fee\u4ed9\u4e4b\u8def<\/a><\/li>\n<\/ul>\n<blockquote data-pid=\"UDyla-1p\"><p>\u539f\u4f5c\u8005\u59d3\u540d\uff1a\u963f\u5b9d\u54e5<br \/>\n\u539f\u51fa\u5904\uff1asegmentfault<br \/>\n\u539f\u6587\u94fe\u63a5\uff1a<a class=\" wrap external\" href=\"https:\/\/link.zhihu.com\/?target=https%3A\/\/segmentfault.com\/a\/1190000022876390\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" data-za-detail-view-id=\"1043\">\u4e86\u4e0d\u8d77\u7684 TypeScript \u5165\u95e8\u6559\u7a0b\uff081.2W\u5b57\uff09<\/a><\/p><\/blockquote>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u539f\u6587\u5730\u5740 349 \u4eba\u8d5e\u540c\u4e86\u8be5\u6587\u7ae0 \u60f3\u5b66\u4e60<\/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-5772","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\/5772","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=5772"}],"version-history":[{"count":0,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/5772\/revisions"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=5772"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=5772"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=5772"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}