{"id":90923,"date":"2024-04-09T18:16:32","date_gmt":"2024-04-09T10:16:32","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/90923.html"},"modified":"2024-04-09T18:16:33","modified_gmt":"2024-04-09T10:16:33","slug":"%e5%9c%a8javascript%e4%b8%ad%e9%81%8d%e5%8e%86%e5%af%b9%e8%b1%a1%e7%9a%84%e6%8a%80%e5%b7%a7","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/90923.html","title":{"rendered":"\u5728JavaScript\u4e2d\u904d\u5386\u5bf9\u8c61\u7684\u6280\u5de7"},"content":{"rendered":"

\"\u5728JavaScript\u4e2d\u904d\u5386\u5bf9\u8c61\u7684\u6280\u5de7\"<\/p>\n

\u5bf9\u8c61\u904d\u5386\u5728JavaScript\u7f16\u7a0b\u4e2d\u662f\u4e00\u79cd\u5e38\u89c1\u4e14\u57fa\u672c\u7684\u64cd\u4f5c\uff0c\u4e3b\u8981\u6280\u5de7\u5305\u62ec\u4f7f\u7528for..in<\/code>\u5faa\u73af\u3001Object.keys()<\/code>\u65b9\u6cd5\u3001Object.values()<\/code>\u65b9\u6cd5\u3001Object.entries()<\/code>\u65b9\u6cd5\u3001\u4ee5\u53ca\u7ed3\u5408\u4f7f\u7528Array.prototype.forEach()<\/code>\u65b9\u6cd5\u3002for..in<\/code>\u5faa\u73af<\/strong>\u80fd\u591f\u904d\u5386\u5bf9\u8c61\u7684\u53ef\u679a\u4e3e\u5c5e\u6027\uff0c\u5305\u62ec\u7ee7\u627f\u7684\u5c5e\u6027\u3002\u7136\u800c\uff0c\u5f53\u4f60\u53ea\u60f3\u904d\u5386\u5bf9\u8c61\u672c\u8eab\u7684\u5c5e\u6027\u65f6\uff0c\u4f60\u901a\u5e38\u4f1a\u914d\u5408hasOwnProperty<\/code>\u65b9\u6cd5\u6765\u68c0\u67e5\u5c5e\u6027\u662f\u5426\u662f\u5bf9\u8c61\u672c\u8eab\u7684\u5c5e\u6027\u3002\u6b64\u5916\uff0c\u8fd9\u4e9b\u6280\u5de7\u53ef\u4ee5\u6839\u636e\u904d\u5386\u76ee\u7684\u548c\u5bf9\u8c61\u7c7b\u578b\u7075\u6d3b\u8fd0\u7528\u548c\u7ec4\u5408\u3002<\/p>\n<\/p>\n

\u4e00\u3001FOR..IN\u5faa\u73af<\/h3>\n<\/p>\n

for..in<\/code>\u5faa\u73af\u662f\u904d\u5386\u5bf9\u8c61\u5c5e\u6027\u7684\u4f20\u7edf\u65b9\u6cd5\u3002\u5b83\u53ef\u4ee5\u8fed\u4ee3\u5bf9\u8c61\u4e2d\u6240\u6709\u53ef\u679a\u4e3e\u7684\u5c5e\u6027\uff0c\u5305\u62ec\u539f\u578b\u94fe\u4e0a\u7ee7\u627f\u7684\u5c5e\u6027\u3002<\/p>\n<\/p>\n

const object = { a: 1, b: 2, c: 3 };<\/p>\n
for (const key in object) {<\/p>\n
  if (object.hasOwnProperty(key)) {<\/p>\n
    console.log(key, object[key]);<\/p>\n
  }<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u4f7f\u7528for..in<\/code>\u65f6\uff0c\u901a\u5e38\u9700\u8981\u4f7f\u7528hasOwnProperty<\/code>\u65b9\u6cd5\u6765\u8fc7\u6ee4\u6389\u539f\u578b\u94fe\u4e0a\u7684\u5c5e\u6027\uff0c\u53ea\u904d\u5386\u5bf9\u8c61\u672c\u8eab\u62e5\u6709\u7684\u5c5e\u6027\u3002\u8fd9\u53ef\u4ee5\u907f\u514d\u610f\u5916\u904d\u5386\u5230\u539f\u578b\u4e0a\u7684\u5c5e\u6027\uff0c\u8fd9\u4e9b\u5c5e\u6027\u53ef\u80fd\u6765\u81ea\u5bf9\u8c61\u7684\u6784\u9020\u51fd\u6570\u539f\u578b\u6216\u8005\u662f\u7ee7\u627f\u81ea\u5176\u4ed6\u5bf9\u8c61\u3002<\/p>\n<\/p>\n
\u4e8c\u3001OBJECT.KEYS()\u65b9\u6cd5<\/h3>\n<\/p>\n
Object.keys()<\/code>\u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u6570\u7ec4\uff0c\u6570\u7ec4\u4e2d\u5305\u542b\u5bf9\u8c61\u672c\u8eab\u7684\uff08\u4e0d\u7ee7\u627f\u7684\uff09\u6240\u6709\u53ef\u679a\u4e3e\u5c5e\u6027\u7684\u952e\u540d\u3002\u8fd9\u4e2a\u65b9\u6cd5\u5e38\u7528\u4e8e\u83b7\u53d6\u5bf9\u8c61\u5c5e\u6027\u7684\u952e\u540d\uff0c\u7136\u540e\u53ef\u4ee5\u914d\u5408\u6570\u7ec4\u65b9\u6cd5\u8fdb\u884c\u8fdb\u4e00\u6b65\u64cd\u4f5c\u3002<\/p>\n<\/p>\n
const object = { a: 1, b: 2, c: 3 };<\/p>\n
const keys = Object.keys(object);<\/p>\n
keys.forEach((key) => {<\/p>\n
  console.log(key, object[key]);<\/p>\n
});<\/p>\n
<\/code><\/pre>\n<\/p>\n
Object.keys()<\/code>\u65b9\u6cd5\u7ed3\u5408Array.prototype.forEach()<\/code>\u53ef\u4ee5\u975e\u5e38\u65b9\u4fbf\u5730\u904d\u5386\u5bf9\u8c61\u7684\u952e\u548c\u503c\u3002\u8fd9\u79cd\u65b9\u6cd5\u4e0d\u4f1a\u904d\u5386\u5230\u4ece\u539f\u578b\u94fe\u7ee7\u627f\u7684\u5c5e\u6027\uff0c\u56e0\u4e3a\u5b83\u53ea\u8fd4\u56de\u5bf9\u8c61\u672c\u8eab\u5177\u6709\u7684\u5c5e\u6027\u540d\u3002<\/p>\n<\/p>\n
\u4e09\u3001OBJECT.VALUES()\u65b9\u6cd5<\/h3>\n<\/p>\n
\u4e0eObject.keys()<\/code>\u65b9\u6cd5\u7c7b\u4f3c\uff0cObject.values()<\/code>\u8fd4\u56de\u7684\u662f\u4e00\u4e2a\u6570\u7ec4\uff0c\u53ea\u4e0d\u8fc7\u5b83\u5305\u542b\u7684\u662f\u5bf9\u8c61\u672c\u8eab\u7684\u6240\u6709\u53ef\u679a\u4e3e\u5c5e\u6027\u503c\u3002<\/p>\n<\/p>\n
const object = { a: 1, b: 2, c: 3 };<\/p>\n
const values = Object.values(object);<\/p>\n
values.forEach((value) => {<\/p>\n
  console.log(value);<\/p>\n
});<\/p>\n
<\/code><\/pre>\n<\/p>\n
Object.values()<\/code>\u65b9\u6cd5\u7b80\u5316\u4e86\u904d\u5386\u5bf9\u8c61\u5c5e\u6027\u503c\u7684\u8fc7\u7a0b\uff0c\u4f7f\u7528\u8fd9\u4e2a\u65b9\u6cd5\u6211\u4eec\u53ef\u4ee5\u76f4\u63a5\u5f97\u5230\u4e00\u4e2a\u5305\u542b\u6240\u6709\u5c5e\u6027\u503c\u7684\u6570\u7ec4\uff0c\u8fdb\u800c\u53ef\u4ee5\u5f88\u5bb9\u6613\u5730\u8fdb\u884c\u8fed\u4ee3\u6216\u5176\u4ed6\u64cd\u4f5c\u3002<\/p>\n<\/p>\n
\u56db\u3001OBJECT.ENTRIES()\u65b9\u6cd5<\/h3>\n<\/p>\n
Object.entries()<\/code>\u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u6570\u7ec4\uff0c\u5176\u5143\u7d20\u662f\u4e0e\u5bf9\u8c61\u81ea\u8eab\u7684\u53ef\u679a\u4e3e\u5c5e\u6027\u952e\u503c\u5bf9\u76f8\u5bf9\u5e94\u7684\u6570\u7ec4\u3002<\/p>\n<\/p>\n
const object = { a: 1, b: 2, c: 3 };<\/p>\n
const entries = Object.entries(object);<\/p>\n
for (const [key, value] of entries) {<\/p>\n
  console.log(key, value);<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
Object.entries()<\/code>\u8fd4\u56de\u7684\u6570\u7ec4\u5bb9\u6613\u4e0efor...of<\/code>\u7ed3\u6784\u4e00\u8d77\u4f7f\u7528\uff0c\u5141\u8bb8\u6211\u4eec\u904d\u5386\u952e\u548c\u503c\uff0c\u5e76\u4e14\u901a\u8fc7\u6570\u7ec4\u89e3\u6784\u76f4\u63a5\u83b7\u5f97\u6bcf\u4e2a\u952e\u503c\u5bf9\u3002<\/p>\n<\/p>\n
\u4e94\u3001\u7ed3\u5408\u4f7f\u7528MAP\u3001FILTER\u548cREDUCE\u65b9\u6cd5<\/h3>\n<\/p>\n
\u5f53\u9700\u8981\u8fdb\u884c\u66f4\u590d\u6742\u7684\u904d\u5386\u64cd\u4f5c\u65f6\uff0c\u53ef\u4ee5\u5c06\u4e0a\u8ff0\u65b9\u6cd5\u4e0e\u6570\u7ec4\u7684map<\/code>\u3001filter<\/code>\u548creduce<\/code>\u65b9\u6cd5\u7ed3\u5408\u4f7f\u7528\u3002\u8fd9\u4e9b\u9ad8\u9636\u51fd\u6570\u53ef\u4ee5\u5e2e\u52a9\u6211\u4eec\u5728\u904d\u5386\u7684\u540c\u65f6\u6267\u884c\u8fc7\u6ee4\u3001\u6620\u5c04\u6216\u7d2f\u79ef\u7b49\u64cd\u4f5c\u3002<\/p>\n<\/p>\n
const object = { a: 1, b: 2, c: 3 };<\/p>\n
const filteredKeys = Object.keys(object)<\/p>\n
  .filter(key => object[key] > 1)<\/p>\n
  .map(key => key.toUpperCase());<\/p>\n
console.log(filteredKeys); \/\/ ['B', 'C']<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u8fc7\u6ee4\u6389\u4e86\u5c0f\u4e8e\u6216\u7b49\u4e8e1\u7684\u5c5e\u6027\u503c\uff0c\u7136\u540e\u5c06\u5269\u4f59\u7684\u952e\u540d\u8f6c\u6362\u6210\u5927\u5199\u5b57\u6bcd\u3002<\/p>\n<\/p>\n
\u7ed3\u5408\u4f7f\u7528\u8fd9\u4e9b\u6280\u5de7\u53ef\u4ee5\u5728\u4e0d\u540c\u7684\u573a\u666f\u4e0b\u6709\u6548\u904d\u5386JavaScript\u5bf9\u8c61<\/strong>\u3002\u968f\u7740ES6\u53ca\u66f4\u9ad8\u7248\u672c\u7684\u53d1\u5c55\uff0c\u8fd9\u4e9b\u6280\u5de7\u4e5f\u5728\u4e0d\u65ad\u5730\u6f14\u8fdb\uff0c\u589e\u52a0\u4e86\u8bb8\u591a\u4f7f\u5bf9\u8c61\u64cd\u4f5c\u66f4\u52a0\u7b80\u6d01\u548c\u5f3a\u5927\u7684\u65b0\u65b9\u6cd5\u3002\u638c\u63e1\u8fd9\u4e9b\u6280\u5de7\u4e0d\u4ec5\u80fd\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u548c\u6548\u7387\uff0c\u4e5f\u662f\u6210\u4e3a\u4e00\u540d\u66f4\u52a0\u719f\u7ec3\u7684JavaScript\u5f00\u53d1\u8005\u7684\u5173\u952e\u6240\u5728\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
\u5982\u4f55\u5728JavaScript\u4e2d\u904d\u5386\u5bf9\u8c61\u7684\u5c5e\u6027\uff1f<\/strong><\/p>\n
JavaScript\u4e2d\u6709\u51e0\u79cd\u65b9\u6cd5\u53ef\u4ee5\u904d\u5386\u5bf9\u8c61\u7684\u5c5e\u6027\u3002\u4e00\u79cd\u5e38\u89c1\u7684\u65b9\u6cd5\u662f\u4f7f\u7528for…in\u5faa\u73af\u6765\u904d\u5386\u5bf9\u8c61\u7684\u5c5e\u6027\u3002\u4f8b\u5982\uff1a<\/p>\n
for (var key in obj) {\n  if (obj.hasOwnProperty(key)) {\n    console.log(key + ": " + obj[key]);\n  }\n}\n<\/code><\/pre>\n
\u8fd9\u4e2a\u5faa\u73af\u4f1a\u904d\u5386\u5bf9\u8c61\u7684\u6240\u6709\u53ef\u679a\u4e3e\u5c5e\u6027\uff0c\u5e76\u5c06\u5c5e\u6027\u540d\u548c\u5c5e\u6027\u503c\u8f93\u51fa\u5230\u63a7\u5236\u53f0\u3002<\/p>\n
\u53e6\u4e00\u79cd\u65b9\u6cd5\u662f\u4f7f\u7528Object.keys()\u548cArray.forEach()\uff0c\u7ed3\u5408\u8d77\u6765\u53ef\u4ee5\u66f4\u7b80\u6d01\u5730\u904d\u5386\u5bf9\u8c61\u7684\u5c5e\u6027\u3002\u4f8b\u5982\uff1a<\/p>\n
Object.keys(obj).forEach(function(key) {\n  console.log(key + ": " + obj[key]);\n});\n<\/code><\/pre>\n
\u8fd9\u79cd\u65b9\u6cd5\u9996\u5148\u5229\u7528Object.keys()\u65b9\u6cd5\u5c06\u5bf9\u8c61\u7684\u5c5e\u6027\u540d\u4ee5\u6570\u7ec4\u7684\u5f62\u5f0f\u8fd4\u56de\uff0c\u7136\u540e\u4f7f\u7528Array.forEach()\u904d\u5386\u8fd9\u4e2a\u6570\u7ec4\uff0c\u5e76\u8f93\u51fa\u5c5e\u6027\u540d\u548c\u5c5e\u6027\u503c\u3002<\/p>\n
\u6b64\u5916\uff0c\u8fd8\u53ef\u4ee5\u4f7f\u7528Object.entries()\u65b9\u6cd5\u5c06\u5bf9\u8c61\u7684\u5c5e\u6027\u952e\u503c\u5bf9\u4ee5\u6570\u7ec4\u7684\u5f62\u5f0f\u8fd4\u56de\uff0c\u7136\u540e\u4f7f\u7528Array.forEach()\u904d\u5386\u8fd9\u4e2a\u4e8c\u7ef4\u6570\u7ec4\uff0c\u8f93\u51fa\u5c5e\u6027\u540d\u548c\u5c5e\u6027\u503c\u3002<\/p>\n
\u603b\u7ed3\u4e00\u4e0b\uff0cJavaScript\u4e2d\u904d\u5386\u5bf9\u8c61\u7684\u6280\u5de7\u5305\u62ec\u4f7f\u7528for…in\u5faa\u73af\u3001Object.keys()\u914d\u5408Array.forEach()\u4ee5\u53caObject.entries()\u914d\u5408Array.forEach()\u7b49\u65b9\u6cd5\u3002\u6839\u636e\u5177\u4f53\u7684\u9700\u6c42\uff0c\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\u6765\u904d\u5386\u5bf9\u8c61\u7684\u5c5e\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u5bf9\u8c61\u904d\u5386\u5728JavaScript\u7f16\u7a0b\u4e2d\u662f\u4e00\u79cd\u5e38\u89c1\u4e14\u57fa\u672c\u7684\u64cd\u4f5c\uff0c\u4e3b\u8981\u6280\u5de7\u5305\u62ec\u4f7f\u7528for..in\u5faa\u73af\u3001Object. […]","protected":false},"author":3,"featured_media":90924,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/90923"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=90923"}],"version-history":[{"count":0,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/90923\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/90924"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=90923"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=90923"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=90923"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}