{"id":229084,"date":"2021-11-07T09:14:31","date_gmt":"2021-11-07T01:14:31","guid":{"rendered":"https:\/\/lrxjmw.cn\/?p=229084"},"modified":"2021-10-24T15:15:48","modified_gmt":"2021-10-24T07:15:48","slug":"es6-empty-object","status":"publish","type":"post","link":"https:\/\/lrxjmw.cn\/es6-empty-object.html","title":{"rendered":"ES6 \u5224\u65ad\u662f\u5426\u4e3a\u7a7a\u5bf9\u8c61"},"content":{"rendered":"<table>\n<tbody>\n<tr>\n<td style=\"padding: 5px 12px; width: 25px; font-size: 22px; text-align: center; background: #E8E8E8; line-height: 30px; color: #999;\">\u5bfc\u8bfb<\/td>\n<td style=\"padding: 10px 10px 12px; line-height: 20px;\"><strong>\u5728js\u4e2d\u5224\u65ad\u5bf9\u8c61\u662f\u5426\u4e3a\u7a7a\uff0c\u662f\u5341\u5206\u5e38\u89c1\u7684\u64cd\u4f5c\uff0c\u90a3\u4e48\u5728ES6\u4e2d\u6709\u54ea\u4e9b\u5199\u6cd5\u5462\uff1f<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<div   id="j6sjwn9j3u"    style=\"font-size: 14pt; color: white; background-color: black; border-left: red 10px solid; padding-left: 14px; margin-bottom: 20px; margin-top: 20px;\"><strong>ES6 Object.keys()<\/strong><\/div>\n<p>Object.keys()\u662fES6\u4e2d\u7684\u65b0\u65b9\u6cd5, \u8fd4\u56de\u503c\u4e5f\u662f\u5bf9\u8c61\u4e2d\u5c5e\u6027\u540d\u7ec4\u6210\u7684\u6570\u7ec4\uff0c\u5305\u62ec\u5bf9\u8c61\u81ea\u8eab\u7684\uff08\u4e0d\u542b\u7ee7\u627f\u7684\uff09\u6240\u6709\u53ef\u679a\u4e3e\u5c5e\u6027\uff08\u4e0d\u542b Symbol \u5c5e\u6027\uff09\u7684\u952e\u540d\u3002<\/p>\n<pre>Object.keys(obj).length === 0 && obj.constructor === Object  \/\/ true\u8868\u793a\u4e3a\u7a7a\u5bf9\u8c61\uff0cfalse\u4e3a\u975e\u7a7a\u5bf9\u8c61<\/pre>\n<p>\u7f3a\u70b9\uff1a \u90e8\u5206\u6d4f\u89c8\u5668\u4e0d\u652f\u6301\uff0c\u9700\u8981\u901a\u8fc7 babel \u7c7b\u63d2\u4ef6\u8f6c\u4e3a ES5\u3002\u4f7f\u7528\u8303\u4f8b\u5982\u4e0b\uff1a<\/p>\n<pre>\r\nvar data = {};\r\n\r\nvar arr = Object.keys(data);\r\n\r\nalert(arr.length == 0);\/\/true \u5373\u4e3a\u7a7a\u5bf9\u8c61\r\n\r\nvar datas={a:1,b:2};\r\n\r\nvar aRR = Object.keys(datas);\r\n\r\nconsole.log(aRR) -->   ['a','b']\r\n\r\n<\/pre>\n<div   id="j6sjwn9j3u"    style=\"font-size: 14pt; color: white; background-color: black; border-left: red 10px solid; padding-left: 14px; margin-bottom: 20px; margin-top: 20px;\"><strong>\u5c06 json \u5bf9\u8c61\u8f6c\u5316\u4e3a json \u5b57\u7b26\u4e32\uff0c\u518d\u5224\u65ad\u8be5\u5b57\u7b26\u4e32\u662f\u5426\u4e3a\"{}\"<\/strong><\/div>\n<pre>\r\nvar data = {};\r\nvar b = (JSON.stringify(data) == \"{}\");\r\nalert(b);\/\/true\r\n<\/pre>\n<div   id="j6sjwn9j3u"    style=\"font-size: 14pt; color: white; background-color: black; border-left: red 10px solid; padding-left: 14px; margin-bottom: 20px; margin-top: 20px;\"><strong>for in \u5faa\u73af\u5224\u65ad<\/strong><\/div>\n<pre>\r\nvar obj = {};\r\nvar b = function() {\r\n  for(var key in obj) {\r\n    return false;\r\n  }\r\n return true;\r\n}\r\nalert(b());\/\/true\r\n<\/pre>\n<div   id="j6sjwn9j3u"    style=\"font-size: 14pt; color: white; background-color: black; border-left: red 10px solid; padding-left: 14px; margin-bottom: 20px; margin-top: 20px;\"><strong>jquery isEmptyObject()<\/strong><\/div>\n<p>\u6b64\u65b9\u6cd5\u662fjquery\u5c06\u65b9\u6cd53 (for in)\u8fdb\u884c\u5c01\u88c5\uff0c\u4f7f\u7528\u65f6\u9700\u8981\u4f9d\u8d56jquery\u3002<\/p>\n<pre>\r\nvar data = {};\r\nvar b = $.isEmptyObject(data);\r\nalert(b);\/\/true\r\n<\/pre>\n<div   id="j6sjwn9j3u"    style=\"font-size: 14pt; color: white; background-color: black; border-left: red 10px solid; padding-left: 14px; margin-bottom: 20px; margin-top: 20px;\"><strong>Object.getOwnPropertyNames()<\/strong><\/div>\n<p>\u6b64\u65b9\u6cd5\u662f\u4f7f\u7528Object\u5bf9\u8c61\u7684getOwnPropertyNames\u65b9\u6cd5\uff0c\u83b7\u53d6\u5230\u5bf9\u8c61\u4e2d\u7684\u5c5e\u6027\u540d\uff0c\u5b58\u5230\u4e00\u4e2a\u6570\u7ec4\u4e2d\uff0c\u8fd4\u56de\u6570\u7ec4\u5bf9\u8c61\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u5224\u65ad\u6570\u7ec4\u7684length\u6765\u5224\u65ad\u6b64\u5bf9\u8c61\u662f\u5426\u4e3a\u7a7a\u3002<\/p>\n<p>\u6ce8\u610f\uff1a\u6b64\u65b9\u6cd5\u4e0d\u517c\u5bb9ie8\uff0c\u5176\u4f59\u6d4f\u89c8\u5668\u6ca1\u6709\u6d4b\u8bd5\u3002<\/p>\n<pre>\r\nvar data = {};\r\nvar arr = Object.getOwnPropertyNames(data);\r\nalert(arr.length == 0);\/\/true\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Object.keys()\u662fES6\u4e2d\u7684\u65b0\u65b9\u6cd5, \u8fd4\u56de\u503c\u4e5f\u662f\u5bf9\u8c61\u4e2d\u5c5e\u6027\u540d\u7ec4\u6210\u7684\u6570\u7ec4\uff0c\u5305\u62ec\u5bf9\u8c61\u81ea\u8eab\u7684\uff08\u4e0d\u542b\u7ee7\u627f\u7684\uff09 [&hellip;]<\/p>\n","protected":false},"author":1903,"featured_media":229087,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[55],"tags":[],"class_list":["post-229084","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-thread"],"acf":[],"_links":{"self":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts\/229084","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/users\/1903"}],"replies":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/comments?post=229084"}],"version-history":[{"count":2,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts\/229084\/revisions"}],"predecessor-version":[{"id":229104,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts\/229084\/revisions\/229104"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/media\/229087"}],"wp:attachment":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/media?parent=229084"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/categories?post=229084"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/tags?post=229084"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}