{"id":1279,"date":"2025-02-10T14:18:59","date_gmt":"2025-02-10T05:18:59","guid":{"rendered":"https:\/\/route-zero.com\/recruit\/route\/1279\/"},"modified":"2025-06-10T14:24:05","modified_gmt":"2025-06-10T05:24:05","slug":"1279","status":"publish","type":"route","link":"https:\/\/route-zero.com\/recruit\/route\/1279\/","title":{"rendered":"TypeScript\u3068\u306f\uff1fJavaScript\u3068\u306e\u9055\u3044\u3092\u521d\u5fc3\u8005\u5411\u3051\u306b\u308f\u304b\u308a\u3084\u3059\u304f\u89e3\u8aac"},"content":{"rendered":"<div>\n<h2>1. \u306f\u3058\u3081\u306b | \u3042\u306a\u305f\u3082\u3053\u3093\u306a\u7d4c\u9a13\u3042\u308a\u307e\u305b\u3093\u304b\uff1f<\/h2>\n<ul>\n<li>\n<p>\u300cJavaScript\u306e\u30b3\u30fc\u30c9\u304c\u52d5\u304b\u306a\u3044\u2026\u3067\u3082\u30a8\u30e9\u30fc\u3082\u51fa\u306a\u3044\u300d<\/p>\n<\/li>\n<li>\n<p>\u300c\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u4e2d\u8eab\u3092\u9593\u9055\u3048\u3066\u4f7f\u3063\u3066\u3044\u3066\u3001\u5f8c\u304b\u3089\u30d0\u30b0\u306b\u6c17\u3065\u3044\u305f\u300d<\/p>\n<\/li>\n<li>\n<p>\u300c\u30c1\u30fc\u30e0\u958b\u767a\u3067\u30b3\u30fc\u30c9\u306e\u8aad\u307f\u3065\u3089\u3055\u306b\u60a9\u3093\u3060\u3053\u3068\u304c\u3042\u308b\u300d<\/p>\n<\/li>\n<\/ul>\n<p>\u305d\u3093\u306a\u6642\u306b\u51fa\u4f1a\u3046\u306e\u304c<strong>TypeScript<\/strong>\u3067\u3059\u3002<\/p>\n<p>\u300c\u578b\u3063\u3066\u5fc5\u8981\uff1f\u300d\u300cJavaScript\u3067\u5341\u5206\u3067\u306f\uff1f\u300d\u3068\u3044\u3046\u58f0\u3082\u3042\u308a\u307e\u3059\u304c\u3001\u5b9f\u306fTypeScript\u3092\u4f7f\u3046\u3053\u3068\u3067\u3001<strong>\u958b\u767a\u306e\u5b89\u5168\u6027\u30fb\u53ef\u8aad\u6027\u30fb\u4fdd\u5b88\u6027\u304c\u5927\u304d\u304f\u5411\u4e0a<\/strong>\u3057\u307e\u3059\u3002<\/p>\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001TypeScript\u3068\u306f\u4f55\u304b\u3001JavaScript\u3068\u306e\u9055\u3044\u3001\u5c0e\u5165\u3059\u308b\u3053\u3068\u3067\u5f97\u3089\u308c\u308b\u5b9f\u52d9\u7684\u30e1\u30ea\u30c3\u30c8\u3092\u3001\u521d\u5fc3\u8005\u306b\u3082\u308f\u304b\u308a\u3084\u3059\u304f\u4e01\u5be7\u306b\u89e3\u8aac\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n<hr>\n<h2>2. TypeScript\u306e\u57fa\u672c\uff1aJavaScript\u3068\u3069\u3046\u9055\u3046\u306e\uff1f<\/h2>\n<h3>TypeScript\u3068\u306f\uff1f<\/h3>\n<p>TypeScript\u306f\u3001Microsoft\u304c\u958b\u767a\u3057\u305fJavaScript\u306e\u30b9\u30fc\u30d1\u30fc\u30bb\u30c3\u30c8\uff08\u62e1\u5f35\u7248\uff09\u3067\u3059\u3002<\/p>\n<ul>\n<li>\n<p>JavaScript\u306b\u300c\u578b\uff08Type\uff09\u300d\u3068\u3044\u3046\u4ed5\u7d44\u307f\u3092\u52a0\u3048\u305f\u3082\u306e<\/p>\n<\/li>\n<li>\n<p>\u6700\u7d42\u7684\u306b\u306fJavaScript\u306b\u5909\u63db\uff08\u30c8\u30e9\u30f3\u30b9\u30d1\u30a4\u30eb\uff09\u3057\u3066\u5b9f\u884c\u3055\u308c\u308b<\/p>\n<\/li>\n<\/ul>\n<p>\u3064\u307e\u308a\u3001TypeScript\u3067\u66f8\u3044\u305f\u30b3\u30fc\u30c9\u306f\u3001<strong>\u30d6\u30e9\u30a6\u30b6\u3084Node.js\u3067\u305d\u306e\u307e\u307e\u52d5\u304f\u308f\u3051\u3067\u306f\u306a\u304f\u3001JavaScript\u306b\u5909\u63db\u3057\u3066\u5b9f\u884c<\/strong>\u3059\u308b\u3068\u3044\u3046\u4ed5\u7d44\u307f\u3067\u3059\u3002<\/p>\n<hr>\n<h3>JavaScript\u3068\u306e\u9055\u3044\u3092\u3056\u3063\u304f\u308a\u6574\u7406<\/h3>\n<ul>\n<li>\n<p><strong>JavaScript<\/strong>\uff1a\u52d5\u7684\u578b\u4ed8\u3051\u8a00\u8a9e\uff08\u578b\u3092\u6c17\u306b\u305b\u305a\u81ea\u7531\u306b\u66f8\u3051\u308b\u304c\u30d0\u30b0\u3082\u51fa\u3084\u3059\u3044\uff09<\/p>\n<\/li>\n<li>\n<p><strong>TypeScript<\/strong>\uff1a\u9759\u7684\u578b\u4ed8\u3051\u8a00\u8a9e\uff08\u578b\u3092\u660e\u793a\u3059\u308b\u3053\u3068\u3067\u30a8\u30e9\u30fc\u3092\u672a\u7136\u306b\u9632\u3052\u308b\uff09<\/p>\n<\/li>\n<\/ul>\n<hr>\n<h3>\u578b\u3092\u6307\u5b9a\u3059\u308b\u3053\u3068\u3067\u4f55\u304c\u5909\u308f\u308b\uff1f<\/h3>\n<pre><code><span>\/\/ TypeScript\u306e\u4f8b<\/span>\r\n<span><span>function<\/span> <span>greet<\/span>(<span>name: string<\/span>): <span>string<\/span> <\/span>{\r\n  <span>return<\/span> <span>\"Hello, \"<\/span> + name;\r\n}<\/code><\/pre>\n<ul>\n<li>\n<p>name: string \u2192 \u3053\u306e\u95a2\u6570\u306e\u5f15\u6570\u304c\u300c\u6587\u5b57\u5217\u578b\u300d\u3067\u3042\u308b\u3053\u3068\u3092\u660e\u793a<\/p>\n<\/li>\n<li>\n<p>: string \u2192 \u623b\u308a\u5024\u3082\u6587\u5b57\u5217\u3067\u3042\u308b\u3053\u3068\u3092\u6307\u5b9a<\/p>\n<\/li>\n<\/ul>\n<p>JavaScript\u3067\u540c\u3058\u3053\u3068\u3092\u3059\u308b\u3068\u3053\u3046\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre><code><span>\/\/ JavaScript\u306e\u4f8b<\/span>\r\n<span><span>function<\/span> <span>greet<\/span>(<span>name<\/span>) <\/span>{\r\n  <span>return<\/span> <span>\"Hello, \"<\/span> + name;\r\n}<\/code><\/pre>\n<p>\u4e00\u898b\u540c\u3058\u3067\u3059\u304c\u3001JavaScript\u3067\u306fname\u304c\u6570\u5024\u3067\u3082\u914d\u5217\u3067\u3082\u95a2\u6570\u304c\u52d5\u3044\u3066\u3057\u307e\u3044\u3001<strong>\u601d\u308f\u306c\u30d0\u30b0\u306e\u539f\u56e0<\/strong>\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<hr>\n<h3>\u8996\u899a\u7684\u306b\u9055\u3044\u3092\u30a4\u30e1\u30fc\u30b8\u3057\u3088\u3046<\/h3>\n<pre><code>JavaScript\uff1a\u4f55\u3067\u3082\u53d7\u3051\u53d6\u308b\u81ea\u7531\u306a\u4e16\u754c\r\n \u2193\r\nTypeScript\uff1a\u30eb\u30fc\u30eb\u304c\u3042\u308b\u304b\u3089\u5b89\u5fc3\u3067\u304d\u308b\u4e16\u754c<\/code><\/pre>\n<p><strong>\u2192 \u3060\u304b\u3089\u3053\u305d\u3001\u898f\u6a21\u304c\u5927\u304d\u304f\u306a\u308b\u307b\u3069TypeScript\u306f\u6709\u52b9\uff01<\/strong><\/p>\n<hr>\n<h2>3. \u3088\u304f\u3042\u308b\u3064\u307e\u305a\u304d\u30dd\u30a4\u30f3\u30c8\uff1aBefore \/ After\u3067\u7406\u89e3\u3059\u308b<\/h2>\n<h3>\u30b1\u30fc\u30b9\uff1a\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u5b58\u5728\u30c1\u30a7\u30c3\u30af\u3092\u5fd8\u308c\u305f<\/h3>\n<p>Before\uff08JavaScript\u3067\u3088\u304f\u3042\u308b\u30d0\u30b0\uff09<\/p>\n<pre><code><span>const<\/span> user = {};\r\n<span>console<\/span>.log(user.name.toUpperCase()); <span>\/\/ TypeError: Cannot read property 'toUpperCase' of undefined<\/span><\/code><\/pre>\n<p>After\uff08TypeScript\u3067\u578b\u3092\u660e\u793a\uff09<\/p>\n<pre><code><span>type<\/span> User = {\r\n  name?: <span>string<\/span>;\r\n};\r\n\r\n<span>const<\/span> user: User = {};\r\n<span>console<\/span>.log(user.name?.toUpperCase()); <span>\/\/ \u30a8\u30e9\u30fc\u306b\u306a\u3089\u306a\u3044\uff08undefined\u3092\u8a31\u5bb9\uff09<\/span><\/code><\/pre>\n<ul>\n<li>\n<p>name?: string \u2192 \u300c\u3042\u3063\u3066\u3082\u306a\u304f\u3066\u3082OK\u300d\u3068\u3044\u3046\u578b\u306e\u8868\u73fe<\/p>\n<\/li>\n<li>\n<p>?. \u2192 \u30aa\u30d7\u30b7\u30e7\u30ca\u30eb\u30c1\u30a7\u30fc\u30f3\uff08\u5b58\u5728\u78ba\u8a8d\u4ed8\u304d\u30a2\u30af\u30bb\u30b9\uff09<\/p>\n<\/li>\n<\/ul>\n<hr>\n<h3>\u30b1\u30fc\u30b9\uff1a\u95a2\u6570\u306e\u623b\u308a\u5024\u306e\u578b\u3092\u9593\u9055\u3048\u305f<\/h3>\n<p>Before\uff08JavaScript\uff09<\/p>\n<pre><code><span><span>function<\/span> <span>add<\/span>(<span>a, b<\/span>) <\/span>{\r\n  <span>return<\/span> a + b;\r\n}\r\n\r\n<span>console<\/span>.log(add(<span>1<\/span>, <span>\"2\"<\/span>)); <span>\/\/ \u7d50\u679c\u306f \"12\"\uff08\u610f\u56f3\u3068\u9055\u3046\uff09<\/span><\/code><\/pre>\n<p>After\uff08TypeScript\uff09<\/p>\n<pre><code><span><span>function<\/span> <span>add<\/span>(<span>a: <span>number<\/span>, b: <span>number<\/span><\/span>): <span>number<\/span> <\/span>{\r\n  <span>return<\/span> a + b; <span>\/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b \"a + b\" \u306e\u578b\u304c\u5408\u3063\u3066\u3044\u308b\u304b\u30c1\u30a7\u30c3\u30af\u3055\u308c\u308b<\/span>\r\n}<\/code><\/pre>\n<p>\u2192 add(1, &#8220;2&#8221;) \u3092\u66f8\u3053\u3046\u3068\u3059\u308b\u3068 <strong>\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc<\/strong>\u306b\uff01<\/p>\n<p><strong>\u3053\u306e\u300c\u4e8b\u524d\u306e\u30c1\u30a7\u30c3\u30af\u300d\u3053\u305d\u304cTypeScript\u306e\u5927\u304d\u306a\u4fa1\u5024<\/strong>\u3067\u3059\u3002<\/p>\n<hr>\n<h3>\u3010\u3088\u304f\u3042\u308b\u8cea\u554f\u3011<\/h3>\n<p><strong>Q. TypeScript\u306f\u5b66\u7fd2\u30b3\u30b9\u30c8\u304c\u9ad8\u3044\uff1f<\/strong><br \/>A. \u6700\u521d\u306f\u5c11\u3057\u3060\u3051\u6238\u60d1\u3044\u307e\u3059\u304c\u3001\u300c\u578b\u300d\u3092\u7406\u89e3\u3059\u308b\u3060\u3051\u3067\u3050\u3063\u3068\u8aad\u307f\u3084\u3059\u304f\u306a\u308a\u3001\u4fdd\u5b88\u304c\u5727\u5012\u7684\u306b\u697d\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p><strong>Q. \u5c0f\u898f\u6a21\u306a\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u306b\u3082\u5fc5\u8981\uff1f<\/strong><br \/>A. \u5c0f\u898f\u6a21\u3067\u3082\u300c\u30d0\u30b0\u3092\u6e1b\u3089\u3057\u305f\u3044\u300d\u300c\u53ef\u8aad\u6027\u3092\u4e0a\u3052\u305f\u3044\u300d\u306a\u3089\u5c0e\u5165\u30e1\u30ea\u30c3\u30c8\u306f\u5341\u5206\u306b\u3042\u308a\u307e\u3059\u3002<\/p>\n<hr>\n<h2>4. \u307e\u3068\u3081 | TypeScript\u306e\u9b45\u529b\u3068\u6b21\u306e\u30b9\u30c6\u30c3\u30d7<\/h2>\n<p><strong>TypeScript\u306f\u3001JavaScript\u306b\u578b\u306e\u4ed5\u7d44\u307f\u3092\u52a0\u3048\u308b\u3053\u3068\u3067\u300c\u5b89\u5168\u6027\u300d\u3068\u300c\u898b\u901a\u3057\u306e\u826f\u3055\u300d\u3092\u624b\u306b\u5165\u308c\u3089\u308c\u308b\u5f37\u529b\u306a\u30c4\u30fc\u30eb<\/strong>\u3067\u3059\u3002<\/p>\n<p>\u521d\u5fc3\u8005\u306e\u3046\u3061\u306f\u300c\u5c11\u3057\u9762\u5012\u300d\u3068\u611f\u3058\u308b\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u304c\u3001\u305d\u308c\u3092\u4e0a\u56de\u308b\u307b\u3069\u306e\u6069\u6075\u304c\u5f97\u3089\u308c\u307e\u3059\u3002\u7279\u306b\u3001\u8907\u6570\u4eba\u3067\u306e\u958b\u767a\u3084\u4e2d\u301c\u9577\u671f\u7684\u306a\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u3092\u8003\u3048\u308b\u306a\u3089\u3001\u65e9\u3081\u306e\u5c0e\u5165\u304c\u304a\u3059\u3059\u3081\u3067\u3059\u3002<\/p>\n<hr>\n<h3>\u6b21\u306b\u8aad\u3080\u3068\u7406\u89e3\u304c\u6df1\u307e\u308b\u8a18\u4e8b<\/h3>\n<ul>\n<li>\n<p>JavaScript\u306e\u52d5\u7684\u578b\u4ed8\u3051\u306e\u843d\u3068\u3057\u7a74\u3068\u306f\uff1f<\/p>\n<\/li>\n<li>\n<p>TypeScript\u306e\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\uff08interface\uff09\u306e\u4f7f\u3044\u65b9<\/p>\n<\/li>\n<li>\n<p>\u578b\u30a2\u30ce\u30c6\u30fc\u30b7\u30e7\u30f3\u3068\u306f\uff1fTypeScript\u521d\u5fc3\u8005\u306e\u305f\u3081\u306e\u5165\u9580<\/p>\n<\/li>\n<li>\n<p>tsconfig.json\u306e\u57fa\u672c\u8a2d\u5b9a\u3068\u305d\u306e\u610f\u5473\u3092\u89e3\u8aac<\/p>\n<\/li>\n<li>\n<p>React + TypeScript\u306e\u57fa\u672c\u69cb\u6210\u3092\u5b66\u3076<\/p>\n<\/li>\n<\/ul>\n<p>\u307e\u305a\u306f\u624b\u5143\u3067\u300cJavaScript \u2192 TypeScript\u306b\u66f8\u304d\u63db\u3048\u3066\u307f\u308b\u300d\u3053\u3068\u304b\u3089\u59cb\u3081\u3066\u307f\u307e\u3057\u3087\u3046\u3002\u5b66\u7fd2\u30b5\u30a4\u30c8\u3084\u30b5\u30f3\u30c9\u30dc\u30c3\u30af\u30b9\u74b0\u5883\u3092\u6d3b\u7528\u3057\u3066\u3001\u5b9f\u969b\u306b\u624b\u3092\u52d5\u304b\u3059\u3053\u3068\u304c\u7406\u89e3\u3078\u306e\u4e00\u756a\u306e\u8fd1\u9053\u3067\u3059\u3002<\/p>\n<h3>\u3010\u5916\u90e8\u30ea\u30f3\u30af\u3011<\/h3>\n<p><a href=\"https:\/\/www.typescriptlang.org\/\">TypeScript\u516c\u5f0f\u30b5\u30a4\u30c8<\/a><\/p>\n<p><a href=\"https:\/\/developer.mozilla.org\/ja\/docs\/Web\/JavaScript\">MDN Web Docs: JavaScript<\/a><\/p>\n<p><a href=\"https:\/\/developer.mozilla.org\/ja\/docs\/Web\/JavaScript\/Reference\/Operators\/Optional_chaining\">MDN Web Docs: Optional chaining<\/a><\/p>\n<p><a href=\"https:\/\/developer.mozilla.org\/ja\/docs\/Web\/JavaScript\/Reference\/Statements\/async_function\">MDN Web Docs: async function<\/a><\/p>\n<h3>\u3010\u5185\u90e8\u30ea\u30f3\u30af\u3011<\/h3>\n<p><a href=\"https:\/\/route-zero.com\/recruit\/route\/1109\/\">JavaScript\u3067\u3088\u304f\u767a\u751f\u3059\u308b\u30a8\u30e9\u30fc\u306e\u539f\u56e0\u3068\u5bfe\u7b56\u3092\u5177\u4f53\u4f8b\u4ed8\u304d\u3067\u89e3\u8aac<\/a><\/p>\n<p><a href=\"https:\/\/route-zero.com\/recruit\/route\/965\/\">JavaScript\u306e\u914d\u5217\u30fbJSON\u30fbmap\u30fbMap\uff1a\u30c7\u30fc\u30bf\u64cd\u4f5c\u8853<\/a><\/p>\n<p><a href=\"https:\/\/route-zero.com\/recruit\/route\/917\/\">JavaScript\u306e\u30b3\u30fc\u30eb\u30d0\u30c3\u30af\u304c\u308f\u304b\u3089\u306a\u3044\uff1f\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3\u5b9f\u4f8b\u3067\u3084\u3055\u3057\u304f\u89e3\u8aac\uff01<\/a><\/p>\n<p><a href=\"https:\/\/route-zero.com\/recruit\/route\/1128\/\">JavaScript\u306eAjax\u5b8c\u5168\u5165\u9580\uff5cfetch\u306e\u4f7f\u3044\u65b9\u30fbCORS\u30a8\u30e9\u30fc\u306e\u5bfe\u51e6\u30fb\u975e\u540c\u671f\u901a\u4fe1\u306e\u57fa\u672c\u3092\u89e3\u8aac<\/a><\/p>\n<p><a href=\"https:\/\/route-zero.com\/recruit\/route\/1219\/\">\u3010\u5b8c\u5168\u7248\u3011\u578b\u306e\u5909\u63db\u3068\u306f\uff1fJava\u30fbJavaScript\u30fbTypeScript\u3067\u5fb9\u5e95\u7406\u89e3\u3059\u308b\u578b\u306e\u6271\u3044\u65b9<\/a><\/p>\n<p><a href=\"https:\/\/route-zero.com\/recruit\/route\/1205\/\">JavaScript\u3067CORS\u30a8\u30e9\u30fc\u304c\u51fa\u305f\u3068\u304d\u306e\u539f\u56e0\u3068\u5bfe\u51e6\u6cd5\u3092\u5fb9\u5e95\u89e3\u8aac<\/a><\/p>\n<p><a href=\"https:\/\/route-zero.com\/recruit\/route\/1136\/\">JavaScript\u4e2d\u7d1a\u8005\u3078\u306e\u30b9\u30c6\u30c3\u30d7\u30a2\u30c3\u30d7\uff5c\u5b9f\u52d9\u3067\u4f7f\u3048\u308b\u30c6\u30af\u30cb\u30c3\u30af10\u9078<\/a><\/p>\n<\/div>\n","protected":false},"featured_media":1280,"template":"","_links":{"self":[{"href":"https:\/\/route-zero.com\/recruit\/wp-json\/wp\/v2\/route\/1279"}],"collection":[{"href":"https:\/\/route-zero.com\/recruit\/wp-json\/wp\/v2\/route"}],"about":[{"href":"https:\/\/route-zero.com\/recruit\/wp-json\/wp\/v2\/types\/route"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/route-zero.com\/recruit\/wp-json\/wp\/v2\/media\/1280"}],"wp:attachment":[{"href":"https:\/\/route-zero.com\/recruit\/wp-json\/wp\/v2\/media?parent=1279"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}