{"id":12061,"date":"2023-11-28T22:41:51","date_gmt":"2023-11-28T14:41:51","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=12061"},"modified":"2023-11-30T17:48:19","modified_gmt":"2023-11-30T09:48:19","slug":"javascript-zhong-wei-shen-metypeof-null-fan-huiobj","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/11\/28\/javascript-zhong-wei-shen-metypeof-null-fan-huiobj\/","title":{"rendered":"JavaScript \u4e2d\u4e3a\u4ec0\u4e48 typeof null \u8fd4\u56de object\uff1f\u5982\u4f55\u68c0\u67e5\u4e00\u4e2a\u503c\u662f\u5426\u4e3a null\uff1f"},"content":{"rendered":"<p>\u5728 JavaScript \u4e2d\uff0c<code>typeof null<\/code> \u8fd4\u56de <code>'object'<\/code> \u662f\u4e00\u4e2a\u5386\u53f2\u9057\u7559\u95ee\u9898\uff0c\u5b9e\u9645\u4e0a\u662f JavaScript \u8bed\u8a00\u672c\u8eab\u7684\u4e00\u4e2a\u8bbe\u8ba1\u7f3a\u9677\u3002<\/p>\n<p>\u8fd9\u4e2a\u95ee\u9898\u6700\u521d\u51fa\u73b0\u5728 JavaScript \u7684\u65e9\u671f\u7248\u672c\u4e2d\uff0c\u5f53\u65f6 JavaScript \u7684\u503c\u662f\u4ee5 32 \u4f4d\u4e8c\u8fdb\u5236\u8868\u793a\u7684\u7c7b\u578b\u6807\u7b7e\u6765\u5b58\u50a8\u7684\uff0c<code>null<\/code> \u7684\u7c7b\u578b\u6807\u7b7e\u88ab\u9519\u8bef\u5730\u6807\u8bb0\u4e3a 0\uff0c\u8fd9\u4e2a\u6807\u8bb0\u4ee3\u8868\u4e86\u5bf9\u8c61\u3002\u56e0\u6b64\uff0c<code>typeof null<\/code> \u8fd4\u56de\u4e86 <code>'object'<\/code>\u3002<\/p>\n<p>\u8981\u68c0\u67e5\u4e00\u4e2a\u503c\u662f\u5426\u4e3a <code>null<\/code>\uff0c\u53ef\u4ee5\u4f7f\u7528\u4e25\u683c\u76f8\u7b49\u8fd0\u7b97\u7b26 <code>===<\/code> \u8fdb\u884c\u6bd4\u8f83\u3002\u56e0\u4e3a <code>null<\/code> \u662f\u4e00\u4e2a\u539f\u59cb\u503c\uff0c\u4ee3\u8868\u201c\u7a7a\u201d\u7684\u5bf9\u8c61\u5f15\u7528\uff0c\u4e0e\u4efb\u4f55\u5bf9\u8c61\u6216\u5176\u4ed6\u539f\u59cb\u503c\u90fd\u4e0d\u76f8\u7b49\uff08\u5305\u62ec\u5b83\u81ea\u8eab\uff09\u3002\u56e0\u6b64\uff0c\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u65b9\u5f0f\u68c0\u67e5\u4e00\u4e2a\u503c\u662f\u5426\u4e3a <code>null<\/code>\uff1a<\/p>\n<pre><code class=\"language-javascript\">let value = null;\n\nif (value === null) {\n    console.log('The value is null.');\n} else {\n    console.log('The value is not null.');\n}\n<\/code><\/pre>\n<p>\u8fd9\u79cd\u65b9\u5f0f\u5229\u7528\u4e86\u4e25\u683c\u76f8\u7b49\u8fd0\u7b97\u7b26\uff0c\u786e\u4fdd\u53ea\u6709\u5f53\u503c\u4e25\u683c\u7b49\u4e8e <code>null<\/code> \u65f6\u6761\u4ef6\u624d\u4f1a\u6210\u7acb\u3002\u8fd9\u662f\u76ee\u524d\u6700\u5e38\u7528\u7684\u68c0\u67e5\u503c\u662f\u5426\u4e3a <code>null<\/code> \u7684\u65b9\u6cd5\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 JavaScript \u4e2d\uff0ctypeof null \u8fd4\u56de &#8216;object&#8217; \u662f\u4e00\u4e2a\u5386\u53f2\u9057\u7559\u95ee\u9898\uff0c\u5b9e\u9645\u4e0a\u662f J [&hellip;]<\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[115],"tags":[],"class_list":["post-12061","post","type-post","status-publish","format-standard","hentry","category-javascript"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/12061","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=12061"}],"version-history":[{"count":2,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/12061\/revisions"}],"predecessor-version":[{"id":13609,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/12061\/revisions\/13609"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=12061"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=12061"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=12061"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}