{"id":12756,"date":"2023-11-28T23:05:21","date_gmt":"2023-11-28T15:05:21","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=12756"},"modified":"2023-11-29T21:52:24","modified_gmt":"2023-11-29T13:52:24","slug":"javascript-zhongin-yun-suan-fu-heobject-hasownprop","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/11\/28\/javascript-zhongin-yun-suan-fu-heobject-hasownprop\/","title":{"rendered":"JavaScript \u4e2d in \u8fd0\u7b97\u7b26\u548c Object.hasOwnProperty \u65b9\u6cd5\u6709\u4ec0\u4e48\u533a\u522b\uff1f"},"content":{"rendered":"<p>\u5728 JavaScript \u4e2d\uff0c<code>in<\/code> \u8fd0\u7b97\u7b26\u548c <code>Object.hasOwnProperty<\/code> \u65b9\u6cd5\u90fd\u7528\u4e8e\u68c0\u67e5\u5bf9\u8c61\u4e2d\u662f\u5426\u5b58\u5728\u6307\u5b9a\u7684\u5c5e\u6027\uff0c\u4f46\u5b83\u4eec\u6709\u4e00\u4e9b\u533a\u522b\uff1a<\/p>\n<ol>\n<li>\n<p><strong><code>in<\/code> \u8fd0\u7b97\u7b26\uff1a<\/strong><\/p>\n<ul>\n<li><code>in<\/code> \u8fd0\u7b97\u7b26\u7528\u4e8e\u68c0\u67e5\u5bf9\u8c61\u4e2d\u662f\u5426\u5b58\u5728\u6307\u5b9a\u7684\u5c5e\u6027\u540d\uff08\u5305\u62ec\u539f\u578b\u94fe\u4e2d\u7684\u5c5e\u6027\uff09\u3002<\/li>\n<li>\u5982\u679c\u5c5e\u6027\u5b58\u5728\u4e8e\u5bf9\u8c61\u672c\u8eab\u6216\u5176\u539f\u578b\u94fe\u4e2d\uff0c\u5219\u8fd4\u56de <code>true<\/code>\uff0c\u5426\u5219\u8fd4\u56de <code>false<\/code>\u3002<\/li>\n<li>\u4f8b\u5982\uff0c<code>'propertyName' in obj<\/code> \u4f1a\u68c0\u67e5 <code>obj<\/code> \u53ca\u5176\u539f\u578b\u94fe\u4e2d\u662f\u5426\u6709\u540d\u4e3a <code>'propertyName'<\/code> \u7684\u5c5e\u6027\u3002<\/li>\n<\/ul>\n<pre><code class=\"language-javascript\">let obj = { a: 1, b: 2 };\nconsole.log('a' in obj); \/\/ \u8f93\u51fa true\uff0c\u56e0\u4e3a 'a' \u5b58\u5728\u4e8e obj \u4e2d\nconsole.log('toString' in obj); \/\/ \u8f93\u51fa true\uff0c\u56e0\u4e3a 'toString' \u5b58\u5728\u4e8e obj \u7684\u539f\u578b\u94fe\u4e2d\n<\/code><\/pre>\n<\/li>\n<li>\n<p><strong><code>Object.hasOwnProperty<\/code> \u65b9\u6cd5\uff1a<\/strong><\/p>\n<ul>\n<li><code>Object.hasOwnProperty<\/code> \u662f\u5bf9\u8c61\u7684\u65b9\u6cd5\uff0c\u7528\u4e8e\u68c0\u67e5\u5c5e\u6027\u662f\u5426\u5b58\u5728\u4e8e\u5bf9\u8c61\u81ea\u8eab\uff0c\u800c\u4e0d\u4f1a\u68c0\u67e5\u539f\u578b\u94fe\u3002<\/li>\n<li>\u5982\u679c\u5c5e\u6027\u662f\u5bf9\u8c61\u81ea\u8eab\u7684\u76f4\u63a5\u5c5e\u6027\uff08\u975e\u7ee7\u627f\u5c5e\u6027\uff09\uff0c\u5219\u8fd4\u56de <code>true<\/code>\uff0c\u5426\u5219\u8fd4\u56de <code>false<\/code>\u3002<\/li>\n<\/ul>\n<pre><code class=\"language-javascript\">let obj = { a: 1, b: 2 };\nconsole.log(obj.hasOwnProperty('a')); \/\/ \u8f93\u51fa true\uff0c\u56e0\u4e3a 'a' \u662f obj \u81ea\u8eab\u7684\u5c5e\u6027\nconsole.log(obj.hasOwnProperty('toString')); \/\/ \u8f93\u51fa false\uff0c\u56e0\u4e3a 'toString' \u4e0d\u662f obj \u81ea\u8eab\u7684\u5c5e\u6027\n<\/code><\/pre>\n<\/li>\n<\/ol>\n<p>\u603b\u7684\u6765\u8bf4\uff0c<code>in<\/code> \u8fd0\u7b97\u7b26\u4f1a\u68c0\u67e5\u5c5e\u6027\u662f\u5426\u5b58\u5728\u4e8e\u5bf9\u8c61\u53ca\u5176\u539f\u578b\u94fe\u4e2d\uff0c\u800c <code>Object.hasOwnProperty<\/code> \u65b9\u6cd5\u53ea\u68c0\u67e5\u5c5e\u6027\u662f\u5426\u5b58\u5728\u4e8e\u5bf9\u8c61\u81ea\u8eab\uff0c\u4e0d\u4f1a\u68c0\u67e5\u539f\u578b\u94fe\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 JavaScript \u4e2d\uff0cin \u8fd0\u7b97\u7b26\u548c Object.hasOwnProperty \u65b9\u6cd5\u90fd\u7528\u4e8e\u68c0\u67e5\u5bf9\u8c61\u4e2d [&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-12756","post","type-post","status-publish","format-standard","hentry","category-javascript"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/12756","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=12756"}],"version-history":[{"count":2,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/12756\/revisions"}],"predecessor-version":[{"id":13523,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/12756\/revisions\/13523"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=12756"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=12756"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=12756"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}