{"id":4914,"date":"2023-04-11T21:38:32","date_gmt":"2023-04-11T12:38:32","guid":{"rendered":"https:\/\/engineering.webstudio168.jp\/?p=4914"},"modified":"2023-04-11T21:38:33","modified_gmt":"2023-04-11T12:38:33","slug":"javascript-for-in","status":"publish","type":"post","link":"https:\/\/engineering.webstudio168.jp\/blog\/javascript-for-in\/","title":{"rendered":"JavaScript for-in\u306e\u4f7f\u3044\u65b9\u3068\u30b5\u30f3\u30d7\u30eb\u30b9\u30af\u30ea\u30d7\u30c8 &#8211; \u521d\u5fc3\u8005\u5411\u3051\u30c1\u30e5\u30fc\u30c8\u30ea\u30a2\u30eb"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_87_1 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">\u76ee\u6b21<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/engineering.webstudio168.jp\/blog\/javascript-for-in\/#for-in%E3%81%AE%E3%82%B5%E3%83%B3%E3%83%97%E3%83%AB\" >for-in\u306e\u30b5\u30f3\u30d7\u30eb<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/engineering.webstudio168.jp\/blog\/javascript-for-in\/#for-in%E6%96%87%E3%81%AE%E4%BD%BF%E3%81%84%E6%96%B9\" >for-in\u6587\u306e\u4f7f\u3044\u65b9<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/engineering.webstudio168.jp\/blog\/javascript-for-in\/#for-in%E3%83%AB%E3%83%BC%E3%83%97%E3%81%AE%E6%B3%A8%E6%84%8F%E7%82%B9\" >for-in\u30eb\u30fc\u30d7\u306e\u6ce8\u610f\u70b9<\/a><\/li><\/ul><\/nav><\/div>\n\n<p class=\"wp-block-paragraph\">JavaScript\u306e<code>for...in<\/code>\u30eb\u30fc\u30d7\u306f\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u53cd\u5fa9\u51e6\u7406\u3059\u308b\u305f\u3081\u306e\u69cb\u6587\u3067\u3059\u3002<code>for...in<\/code>\u30eb\u30fc\u30d7\u3092\u4f7f\u7528\u3059\u308b\u3068\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u5185\u306e\u3059\u3079\u3066\u306e\u5217\u6319\u53ef\u80fd\u306a\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u53cd\u5fa9\u51e6\u7406\u3057\u3001\u305d\u308c\u305e\u308c\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u30ad\u30fc\u3092\u53d6\u5f97\u3067\u304d\u307e\u3059\u3002for-in\u6587\u3068\u306f\u8a00\u3044\u307e\u3059\u304c\u3001<a href=\"https:\/\/engineering.webstudio168.jp\/blog\/javascript-for-tutorial\/\">for\u6587<\/a>\u306b\u30ab\u30c6\u30b4\u30e9\u30a4\u30ba\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"for-in%E3%81%AE%E3%82%B5%E3%83%B3%E3%83%97%E3%83%AB\"><\/span>for-in\u306e\u30b5\u30f3\u30d7\u30eb<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><code>for...in<\/code>\u30eb\u30fc\u30d7\u3092\u4f7f\u7528\u3057\u3066\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u53cd\u5fa9\u51e6\u7406\u3059\u308b\u30b5\u30f3\u30d7\u30eb\u30b9\u30af\u30ea\u30d7\u30c8\u3092\u793a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism undefined-numbers lang-js\" data-file=\"for-in-sample.js\" data-lang=\"JavaScript\"><code>let person = {\n  name: &#39;Hanako&#39;,\n  age: 30,\n  city: &#39;Tokyo&#39;\n};\n\nfor (let key in person) {\n  console.log(key + &#39;: &#39; + person[key]);\n}\n\n\/\/ \u5b9f\u884c\u7d50\u679c\nname: Hanako\nage: 30\ncity: Tokyo<\/code><\/pre><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u306e\u30b9\u30af\u30ea\u30d7\u30c8\u3067\u306f\u3001<code>person<\/code>\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u53cd\u5fa9\u51e6\u7406\u3057\u3001\u5404\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u30ad\u30fc\u3068\u5024\u3092\u30b3\u30f3\u30bd\u30fc\u30eb\u306b\u51fa\u529b\u3057\u3066\u3044\u307e\u3059\u3002<code>for...in<\/code>\u30eb\u30fc\u30d7\u3067\u53cd\u5fa9\u51e6\u7406\u3059\u308b\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u5909\u6570\u540d\u306f<code>person<\/code>\u3067\u3042\u308a\u3001<code>for<\/code>\u30eb\u30fc\u30d7\u5185\u3067<code>key<\/code>\u3068\u3044\u3046\u5909\u6570\u540d\u304c\u5b9a\u7fa9\u3055\u308c\u3001\u5404\u53cd\u5fa9\u3067\u73fe\u5728\u306e<strong>\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u30ad\u30fc<\/strong>\u304c\u4ee3\u5165\u3055\u308c\u307e\u3059\u3002<code>console.log()<\/code>\u306f\u3001\u5404\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u30ad\u30fc\u3068\u5024\u3092\u51fa\u529b\u3059\u308b\u305f\u3081\u306b\u4f7f\u7528\u3055\u308c\u307e\u3059\u3002<br>\uff08\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306b\u3064\u3044\u3066\u306f\u300e<a href=\"https:\/\/engineering.webstudio168.jp\/blog\/javascript-what-is-object\/\">JavaScript \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3068\u306f\u4f55\u304b\uff1f\u6982\u8981\u3068\u8a18\u8ff0\u65b9\u6cd5\u3092\u57fa\u790e\u304b\u3089\u89e3\u8aac<\/a>\u300f\u3092\u53c2\u7167\u3057\u3066\u304f\u3060\u3055\u3044\u3002\uff09<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"for-in%E6%96%87%E3%81%AE%E4%BD%BF%E3%81%84%E6%96%B9\"><\/span>for-in\u6587\u306e\u4f7f\u3044\u65b9<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism undefined-numbers lang-js\" data-file=\"for-in-obj.js\" data-lang=\"JavaScript\"><code>for (for\u6587\u5185\u3067\u4f7f\u7528\u3059\u308b\u5909\u6570\u540d in for\u6587\u3067\u53d6\u5f97\u3057\u305f\u3044\u30aa\u30d6\u30b8\u30a7\u30af\u30c8) {\n  \/\/ \u30d7\u30ed\u30d1\u30c6\u30a3\u306b\u5bfe\u3059\u308b\u51e6\u7406\n}<\/code><\/pre><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><code>for(... in ...){}<\/code>\u306e\u4f7f\u3044\u65b9\u306f\u4e0a\u8a18\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002\u4e00\u822c\u7684\u306b<strong>for-in\u6587<\/strong>\u3068\u8868\u8a18\u3055\u308c\u307e\u3059\u304c\u53b3\u5bc6\u306b\u306ffor()\u6587\u306e1\u7a2e\u306b\u3059\u304e\u307e\u305b\u3093\u3002<br>for\u6587\uff1a\u300e<a href=\"https:\/\/engineering.webstudio168.jp\/blog\/javascript-for-tutorial\/\">JavaScript\u306efor\u6587\uff08\u30eb\u30fc\u30d7\u51e6\u7406\uff09\u306e\u4f7f\u3044\u65b9\uff1a\u521d\u5fc3\u8005\u5411\u3051\u30c1\u30e5\u30fc\u30c8\u30ea\u30a2\u30eb<\/a>\u300f<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"for-in%E3%83%AB%E3%83%BC%E3%83%97%E3%81%AE%E6%B3%A8%E6%84%8F%E7%82%B9\"><\/span>for-in\u30eb\u30fc\u30d7\u306e\u6ce8\u610f\u70b9<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">JavaScript\u306e<code>for...in<\/code>\u30eb\u30fc\u30d7\u3092\u4f7f\u7528\u3059\u308b\u5834\u5408\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u6ce8\u610f\u70b9\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u53cd\u5fa9\u9806\u5e8f\u304c\u30d7\u30ed\u30d1\u30c6\u30a3\u304c\u5b9a\u7fa9\u3055\u308c\u305f\u9806\u5e8f\u3068\u306f\u5fc5\u305a\u3057\u3082\u4e00\u81f4\u3057\u306a\u3044<\/strong>\uff1a<code>for...in<\/code>\u30eb\u30fc\u30d7\u3067\u53cd\u5fa9\u51e6\u7406\u3059\u308b\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u9806\u5e8f\u306f\u3001<span class=\"red\">\u30d7\u30ed\u30d1\u30c6\u30a3\u304c\u5b9a\u7fa9\u3055\u308c\u305f\u9806\u5e8f\u3068\u306f\u5fc5\u305a\u3057\u3082\u4e00\u81f4\u3057\u306a\u3044<\/span>\u305f\u3081\u3001\u9806\u5e8f\u306b\u4f9d\u5b58\u3059\u308b\u51e6\u7406\u306b\u306f\u4f7f\u7528\u3057\u306a\u3044\u3053\u3068\u304c\u671b\u307e\u3057\u3044\u3067\u3059\u3002<\/li>\n\n\n\n<li><strong>\u30d7\u30ed\u30c8\u30bf\u30a4\u30d7\u30c1\u30a7\u30fc\u30f3\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u3082\u53cd\u5fa9\u51e6\u7406\u3055\u308c\u308b<\/strong>\uff1a<code>for...in<\/code>\u30eb\u30fc\u30d7\u306f\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u30d7\u30ed\u30c8\u30bf\u30a4\u30d7\u30c1\u30a7\u30fc\u30f3\u306b\u3042\u308b\u30d7\u30ed\u30d1\u30c6\u30a3\u3082\u53cd\u5fa9\u51e6\u7406\u3059\u308b\u305f\u3081\u3001<span class=\"red\">\u610f\u56f3\u3057\u306a\u3044\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u53cd\u5fa9\u51e6\u7406\u3059\u308b\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002<\/span>\u30d7\u30ed\u30c8\u30bf\u30a4\u30d7\u30c1\u30a7\u30fc\u30f3\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u53cd\u5fa9\u51e6\u7406\u3057\u305f\u304f\u306a\u3044\u5834\u5408\u306f\u3001<code>hasOwnProperty()<\/code>\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u7528\u3057\u3066\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u81ea\u8eab\u304c\u6301\u3064\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u307f\u3092\u53cd\u5fa9\u51e6\u7406\u3059\u308b\u3088\u3046\u306b\u5236\u5fa1\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/li>\n\n\n\n<li><strong>\u5217\u6319\u53ef\u80fd\u306a\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u307f\u304c\u53cd\u5fa9\u51e6\u7406\u3055\u308c\u308b<\/strong>\uff1a<code>for...in<\/code>\u30eb\u30fc\u30d7\u306f\u3001\u5217\u6319\u53ef\u80fd\u306a\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u307f\u3092\u53cd\u5fa9\u51e6\u7406\u3059\u308b\u305f\u3081\u3001\u5217\u6319\u4e0d\u53ef\u80fd\u306a\u30d7\u30ed\u30d1\u30c6\u30a3\u306f\u53cd\u5fa9\u51e6\u7406\u3055\u308c\u307e\u305b\u3093\u3002\uff08<span class=\"red\">\u30ad\u30fc\u304c\u6587\u5b57\u5217\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u307f\u51e6\u7406<\/span>\u3055\u308c\u3001Symbol\u306f\u7121\u8996\u3055\u308c\u307e\u3059\u3002\uff09<\/li>\n\n\n\n<li><strong>\u306a\u308b\u3079\u304f\u914d\u5217\u306b\u5bfe\u3057\u3066\u4f7f\u7528\u3057\u306a\u3044<\/strong>\uff1a<code>for...in<\/code>\u30eb\u30fc\u30d7\u306f\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u53cd\u5fa9\u51e6\u7406\u3059\u308b\u305f\u3081\u306b\u8a2d\u8a08\u3055\u308c\u3066\u304a\u308a\u3001<span class=\"red\">\u914d\u5217\u306b\u5bfe\u3057\u3066\u4f7f\u7528\u3059\u308b\u3068\u3001\u610f\u56f3\u3057\u306a\u3044\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u53cd\u5fa9\u51e6\u7406\u3059\u308b\u3053\u3068\u304c\u3042\u308a\u307e\u3059<\/span>\u3002\u4ee3\u308f\u308a\u306b\u3001<a href=\"https:\/\/engineering.webstudio168.jp\/blog\/javascript-for-tutorial\/\"><code>for<\/code>\u30eb\u30fc\u30d7<\/a>\u3084<a href=\"https:\/\/engineering.webstudio168.jp\/blog\/javascript-foreach\/\"><code>forEach()<\/code>\u30e1\u30bd\u30c3\u30c9<\/a>\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u304c\u671b\u307e\u3057\u3044\u3067\u3059\u3002<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u53c2\u8003\uff1a<a href=\"https:\/\/developer.mozilla.org\/ja\/docs\/Web\/JavaScript\/Reference\/Statements\/for...in\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">https:\/\/developer.mozilla.org\/ja\/docs\/Web\/JavaScript\/Reference\/Statements\/for\u2026in<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>JavaScript\u306efor&#8230;in\u30eb\u30fc\u30d7\u306f\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u53cd\u5fa9\u51e6\u7406\u3059\u308b\u305f\u3081\u306e\u69cb\u6587\u3067\u3059\u3002for&#8230;in\u30eb\u30fc\u30d7\u3092\u4f7f\u7528\u3059\u308b\u3068\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u5185\u306e\u3059\u3079\u3066\u306e\u5217\u6319\u53ef\u80fd\u306a\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u53cd\u5fa9\u51e6\u7406\u3057\u3001\u305d\u308c\u305e\u308c\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u30ad [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":4935,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[55],"tags":[8,83,48],"class_list":["post-4914","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-javascript","tag-javascript","tag-83","tag-48"],"_links":{"self":[{"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/posts\/4914","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/comments?post=4914"}],"version-history":[{"count":16,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/posts\/4914\/revisions"}],"predecessor-version":[{"id":4934,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/posts\/4914\/revisions\/4934"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/media\/4935"}],"wp:attachment":[{"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/media?parent=4914"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/categories?post=4914"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/engineering.webstudio168.jp\/blog\/wp-json\/wp\/v2\/tags?post=4914"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}