{"id":494,"date":"2022-12-24T15:36:54","date_gmt":"2022-12-24T06:36:54","guid":{"rendered":"http:\/\/attacktube.com\/?p=494"},"modified":"2023-09-03T22:40:55","modified_gmt":"2023-09-03T13:40:55","slug":"javascript-typeof%e6%bc%94%e7%ae%97%e5%ad%90","status":"publish","type":"post","link":"https:\/\/attacktube.com\/?p=494","title":{"rendered":"\u3010JavaScript\u3011typeof\u6f14\u7b97\u5b50"},"content":{"rendered":"\n<p>&#8211;JavaScript Good parts P19 \u3053\u3053\u304b\u3089&#8211;<br>typeof\u3092\u5229\u7528\u3059\u308b\u3068\u3001number\u3001string\u3001boolean\u3001undefined\u3001function\u3001object\u3068\u3044\u3046\u5024\u3092\u5f97\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u3002\u305f\u3060\u3057\u30aa\u30da\u30e9\u30f3\u30c9\u304c\u914d\u5217\u304bnull\u3060\u3063\u305f\u5834\u5408\u306b\u306f\u3001\u7d50\u679c\u306fobject\u306b\u306a\u3063\u3066\u3057\u307e\u3046\u3002\u3053\u308c\u306f\u4ed5\u69d8\u306b\u304a\u3051\u308b\u30df\u30b9\u3067\u3042\u308b\u3002<br>&#8211;JavaScript Good parts P19 \u3053\u3053\u304b\u3089&#8211;<\/p>\n\n\n\n<!--more-->\n\n\n\n<br>\n<script async=\"\" src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-3461056110605997\" crossorigin=\"anonymous\"><\/script>\n<ins class=\"adsbygoogle\" style=\"display:block; text-align:center;\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\" data-ad-client=\"ca-pub-3461056110605997\" data-ad-slot=\"3137443461\"><\/ins>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script>\n<br>\n\n\n\n<p>&#8211;JavaScript Good parts P27 \u3053\u3053\u304b\u3089&#8211;<br>typeof\u6f14\u7b97\u5b50\u306f\u30d7\u30ed\u30d1\u30c6\u30a3\u306e\u5909\u6570\u578b\u3092\u8abf\u3079\u308b\u306e\u306b\u975e\u5e38\u306b\u8a33\u306b\u7acb\u3064\u3002<br>&#8211;JavaScript Good parts P27 \u3053\u3053\u304b\u3089&#8211;<br><br>&#8211;JavaScript Good parts P119 \u3053\u3053\u304b\u3089&#8211;<br>typof\u6f14\u7b97\u5b50\u306f\u305d\u306e\u30aa\u30da\u30e9\u30f3\u30c9\u306e\u5909\u6570\u578b\u3092\u8868\u3059\u6587\u5b57\u5217\u3092\u8fd4\u3059\u3002<br>&#8211;JavaScript Good parts P119 \u3053\u3053\u304b\u3089&#8211;<br><br>\u89e3\u8aac<br>\u30aa\u30da\u30e9\u30f3\u30c9(operand)\u306f\u88ab\u6f14\u7b97\u5b50\u3067\u3042\u308b\u3002<br>typeof\u6f14\u7b97\u5b50\u306f\u3001\u30aa\u30da\u30e9\u30f3\u30c9\u304cnull\u3068\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3068\u914d\u5217\u306e\u5834\u5408\u306f\u300cobject\u300d\u3092\u8fd4\u3059\u3053\u3068\u306b\u6ce8\u610f\u3059\u308b\u3002<br><br>\u3053\u306e3\u3064\u306e\u5224\u5b9a\u306f\u3069\u3046\u3059\u308b\u304b\uff1f<br>null\u304b\u3069\u3046\u304b\u306e\u5224\u5b9a\u306fnull\u3068\u6bd4\u8f03\u3059\u308b\u3002<br>\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304b\u3069\u3046\u304b\u306e\u5224\u5b9a\u306f\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304c\u771f\u5024(truthy)\u3067\u3042\u308a\u3001typeof\u306e\u5224\u5b9a\u304cobject\u3067\u3042\u308a\u3001Array.isArray\u304cfalse\u3067\u3042\u308b\u3053\u3068\u3092\u4f7f\u3046\u3002<br>\u914d\u5217\u304b\u3069\u3046\u304b\u306e\u5224\u5b9a\u306f\u914d\u5217\u304c\u771f\u5024(truthy)\u3067\u3042\u308a\u3001typeof\u306e\u5224\u5b9a\u304cobject\u3067\u3042\u308a\u3001Array.isArray\u304ctrue\u3067\u3042\u308b\u3053\u3068\u3092\u4f7f\u3046\u3002<\/p>\n\n\n\n<pre><code>\n\nvar add = function (a, b){\n return a + b;\n};\n\nvar array = [100,200,300];\n\nvar buf = null;\n\nvar obj = {\"value\":100};\n\nconsole.log(\"typeof add = \" + typeof add);\/\/function\n\nconsole.log(\"typeof array = \" + typeof array);\/\/Object\n\nconsole.log(\"typeof buf = \" + typeof buf);\/\/Object\n\nconsole.log(\"typeof obj = \" + typeof obj);\/\/Object\n\nconsole.log(\"Array.isArray(add) = \" + Array.isArray(add));\/\/false\n\nconsole.log(\"Array.isArray(array) = \" + Array.isArray(array));\/\/true\n\nconsole.log(\"Array.isArray(buf) = \" + Array.isArray(buf));\/\/false\n\nconsole.log(\"Array.isArray(obj) = \" + Array.isArray(obj));\/\/false\n\nif(buf === null){\n  console.log(\"buf\u306fnull\u3067\u3042\u308b\u3002\");\n}\n\nif(obj &amp;&amp; typeof obj === 'object' &amp;&amp; !Array.isArray(obj)){\n  console.log(\"obj\u306f\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3067\u3042\u308b\u3002\");\n}else{\n  console.log(\"obj\u306f\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3067\u306f\u306a\u3044\u3002\");\n}\n\nif(array &amp;&amp; typeof array === 'object' &amp;&amp; Array.isArray(array)){\n  console.log(\"array\u306f\u914d\u5217\u3067\u3042\u308b\u3002\");\n}else{\n  console.log(\"array\u306f\u914d\u5217\u3067\u306f\u306a\u3044\u3002\");\n}\n\n<\/code><\/pre>\n\n\n\n<p>\n\u53c2\u8003<br>\n<a href=\"https:\/\/hb.afl.rakuten.co.jp\/ichiba\/298338d3.714ded4a.298338d4.abf99259\/?pc=https%3A%2F%2Fitem.rakuten.co.jp%2Fbook%2F5940391%2F&amp;link_type=text&amp;ut=eyJwYWdlIjoiaXRlbSIsInR5cGUiOiJ0ZXh0Iiwic2l6ZSI6IjI0MHgyNDAiLCJuYW0iOjEsIm5hbXAiOiJyaWdodCIsImNvbSI6MSwiY29tcCI6ImRvd24iLCJwcmljZSI6MSwiYm9yIjoxLCJjb2wiOjEsImJidG4iOjEsInByb2QiOjAsImFtcCI6ZmFsc2V9\" target=\"_blank\" rel=\"nofollow sponsored noopener\" style=\"word-wrap:break-word;\">JavaScript\uff1athe good parts \u300c\u826f\u3044\u30d1\u30fc\u30c4\u300d\u306b\u3088\u308b\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9 [ \u30c0\u30b0\u30e9\u30b9\u30fb\u30af\u30ed\u30d5\u30a9\u30fc\u30c9 ]<\/a>\u306eP19\u300127\u3001119<\/p>\n\n\n\n<script type=\"text\/javascript\">\njQuery(function($){\n$(\".jp-video\").hide();\n});\n<\/script>\n","protected":false},"excerpt":{"rendered":"<p>&#8211;JavaScript Good parts P19 \u3053\u3053\u304b\u3089&#8211;typeof\u3092\u5229\u7528\u3059\u308b\u3068\u3001number\u3001string\u3001boolean\u3001undefined\u3001function\u3001object\u3068\u3044\u3046\u5024\u3092\u5f97 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[3],"tags":[],"class_list":["post-494","post","type-post","status-publish","format-standard","hentry","category-javascript"],"jetpack_featured_media_url":"","jetpack-related-posts":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/attacktube.com\/index.php?rest_route=\/wp\/v2\/posts\/494","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/attacktube.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/attacktube.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/attacktube.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/attacktube.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=494"}],"version-history":[{"count":7,"href":"https:\/\/attacktube.com\/index.php?rest_route=\/wp\/v2\/posts\/494\/revisions"}],"predecessor-version":[{"id":4356,"href":"https:\/\/attacktube.com\/index.php?rest_route=\/wp\/v2\/posts\/494\/revisions\/4356"}],"wp:attachment":[{"href":"https:\/\/attacktube.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=494"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/attacktube.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=494"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/attacktube.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=494"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}