{"id":169463,"date":"2024-05-08T16:46:14","date_gmt":"2024-05-08T08:46:14","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/169463.html"},"modified":"2024-05-08T16:46:19","modified_gmt":"2024-05-08T08:46:19","slug":"javascript-%e5%a6%82%e4%bd%95-%e8%a7%a3%e9%99%a4%e4%b8%a4%e4%b8%aa%e5%af%b9%e8%b1%a1%e4%b9%8b%e9%97%b4%e7%9a%84%e5%bc%95%e7%94%a8","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/169463.html","title":{"rendered":"javascript \u5982\u4f55 \u89e3\u9664\u4e24\u4e2a\u5bf9\u8c61\u4e4b\u95f4\u7684\u5f15\u7528"},"content":{"rendered":"

\"javascript<\/p>\n

JavaScript\u63d0\u4f9b\u4e86\u51e0\u79cd\u65b9\u6cd5\u6765\u89e3\u9664\u4e24\u4e2a\u5bf9\u8c61\u4e4b\u95f4\u7684\u5f15\u7528\uff0c\u5176\u4e2d\u5305\u62ec\u5c06\u5f15\u7528\u8bbe\u4e3anull\u3001\u4f7f\u7528WeakMap\u3001\u6df1\u62f7\u8d1d\u5bf9\u8c61\u3001\u4f7f\u7528\u89e3\u6784\u8d4b\u503c<\/strong>\u3002\u5c06\u5f15\u7528\u8bbe\u4e3anull\u662f\u4e00\u79cd\u5e38\u7528\u4e14\u6709\u6548\u7684\u65b9\u6cd5<\/strong>\uff0c\u5b83\u53ef\u4ee5\u5e2e\u52a9\u65ad\u5f00\u5bf9\u8c61\u4e4b\u95f4\u7684\u8054\u7cfb\uff0c\u5e76\u53ef\u4ee5\u901a\u8fc7\u5783\u573e\u56de\u6536\u673a\u5236\u56de\u6536\u4e0d\u518d\u9700\u8981\u7684\u5bf9\u8c61\u5185\u5b58\u3002<\/p>\n<\/p>\n

\u5f53\u5bf9\u8c61A\u6301\u6709\u5bf9\u8c61B\u7684\u5f15\u7528\u65f6\uff0c\u53ea\u8981A\u8fd8\u5b58\u5728\uff0cB\u4e5f\u4e0d\u4f1a\u88ab\u5783\u573e\u56de\u6536\u673a\u5236\u56de\u6536\u3002\u901a\u8fc7\u5c06\u5bf9\u8c61A\u4e2d\u6301\u6709\u7684\u5bf9\u8c61B\u5f15\u7528\u8bbe\u7f6e\u4e3anull\uff0c\u53ef\u4ee5\u6253\u7834\u8fd9\u79cd\u5173\u8054\uff0c\u5141\u8bb8\u5783\u573e\u56de\u6536\u673a\u5236\u72ec\u7acb\u5730\u56de\u6536\u8fd9\u4e24\u4e2a\u5bf9\u8c61\u3002<\/p>\n<\/p>\n

\u4e00\u3001\u8bbe\u4e3aNULL\u4ee5\u89e3\u9664\u5f15\u7528<\/h3>\n<\/p>\n

\u5f53\u6211\u4eec\u60f3\u89e3\u9664\u4e24\u4e2a\u5bf9\u8c61\u4e4b\u95f4\u7684\u5f15\u7528\u5173\u7cfb\u65f6\uff0c\u6211\u4eec\u53ef\u4ee5\u624b\u52a8\u5c06\u5b83\u4eec\u4e4b\u95f4\u7684\u5f15\u7528\u8bbe\u7f6e\u4e3anull\u3002\u8fd9\u662f\u56e0\u4e3a\u5728JavaScript\u4e2d\uff0c\u5f53\u4e00\u4e2a\u5bf9\u8c61\u4e0d\u518d\u88ab\u4efb\u4f55\u53d8\u91cf\u5f15\u7528\u65f6\uff0c\u8be5\u5bf9\u8c61\u4f1a\u6210\u4e3a\u5783\u573e\u56de\u6536\u7684\u5019\u9009\u5bf9\u8c61\u3002\u901a\u8fc7\u5c06\u5bf9\u8c61\u7684\u5f15\u7528\u8bbe\u7f6e\u4e3anull\uff0c\u6211\u4eec\u5b9e\u9645\u4e0a\u662f\u5728\u544a\u8bc9\u5783\u573e\u56de\u6536\u673a\u5236\uff1a\u201c\u8fd9\u4e2a\u5bf9\u8c61\u4e0d\u518d\u9700\u8981\u4e86\u3002\u201d<\/p>\n<\/p>\n

let objectA = {...};<\/p>\n
let objectB = objectA;<\/p>\n
\/\/ \u89e3\u9664objectA\u5bf9objectB\u7684\u5f15\u7528<\/p>\n
objectA = null;<\/p>\n
\/\/ \u5982\u679cobjectB\u4e5f\u4e0d\u518d\u9700\u8981\uff0c\u53ef\u4ee5\u5c06\u5176\u8bbe\u7f6e\u4e3anull<\/p>\n
objectB = null;<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e8c\u3001\u4f7f\u7528\u6df1\u62f7\u8d1d<\/h3>\n<\/p>\n
\u4f7f\u7528\u6df1\u62f7\u8d1d\u53ef\u4ee5\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61\u7684\u526f\u672c\uff0c\u8fd9\u6837\u539f\u59cb\u5bf9\u8c61\u548c\u65b0\u5bf9\u8c61\u4e4b\u95f4\u5c31\u4e0d\u4f1a\u5171\u4eab\u76f8\u540c\u7684\u5f15\u7528\u3002\u6df1\u62f7\u8d1d\u610f\u5473\u7740\u4e0d\u4ec5\u62f7\u8d1d\u5bf9\u8c61\u672c\u8eab\uff0c\u8fd8\u5305\u62ec\u5bf9\u8c61\u5185\u90e8\u5d4c\u5957\u7684\u6240\u6709\u5bf9\u8c61\u3002<\/p>\n<\/p>\n
function deepClone(obj) {<\/p>\n
    return JSON.parse(JSON.stringify(obj));<\/p>\n
}<\/p>\n
let originalObject = {...};<\/p>\n
let clonedObject = deepClone(originalObject);<\/p>\n
\/\/ \u73b0\u5728\uff0coriginalObject\u548cclonedObject\u4e0d\u5b58\u5728\u5f15\u7528\u5173\u7cfb<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0cJSON\u65b9\u6cd5\u53ea\u9002\u7528\u4e8e\u53ef\u4ee5\u88abJSON\u76f4\u63a5\u8868\u793a\u7684\u6570\u636e\u7ed3\u6784\u3002\u5bf9\u4e8e\u67d0\u4e9b\u7279\u6b8a\u5bf9\u8c61\u3001\u5faa\u73af\u5f15\u7528\u3001\u51fd\u6570\u7b49\uff0c\u8fd9\u79cd\u65b9\u6cd5\u53ef\u80fd\u4e0d\u9002\u7528\u3002<\/p>\n<\/p>\n
\u4e09\u3001\u4f7f\u7528WeakMap<\/h3>\n<\/p>\n
WeakMap\u662fECMAScript 2015\uff08\u5373ES6\uff09\u5f15\u5165\u7684\u4e00\u79cd\u65b0\u7684\u6570\u636e\u7ed3\u6784\uff0c\u5b83\u53ea\u5bf9\u952e\u662f\u5bf9\u8c61\u7684\u5f31\u5f15\u7528\uff0c\u5f53\u5bf9\u8c61\u7684\u5176\u4ed6\u5f15\u7528\u88ab\u9500\u6bc1\u65f6\uff0c\u8fd9\u4e9b\u5bf9\u8c61\u80fd\u591f\u88ab\u5783\u573e\u56de\u6536\u3002<\/p>\n<\/p>\n
let obj1 = {...};<\/p>\n
let obj2 = {...};<\/p>\n
let wm = new WeakMap();<\/p>\n
wm.set(obj1, obj2);<\/p>\n
\/\/ \u6b64\u65f6obj1\u548cobj2\u662f\u5173\u8054\u7684\uff0c\u4f46\u662f\u5b83\u4eec\u7684\u5f15\u7528\u662f\u5f31\u5f15\u7528<\/p>\n
\/\/ \u5f53\u5176\u4ed6\u5f15\u7528\u90fd\u6d88\u5931\u65f6\uff0cWeakMap\u4e2d\u7684\u8fd9\u4e9b\u5bf9\u8c61\u53ef\u4ee5\u88ab\u5783\u573e\u56de\u6536<\/p>\n
obj1 = null;<\/p>\n
\/\/ obj2\u73b0\u5728\u53ea\u5b58\u5728\u4e8eWeakMap\u4e2d\u4f5c\u4e3a\u5f31\u5f15\u7528\uff0c\u5b83\u4f1a\u5728\u4e0d\u5f71\u54cd\u5783\u573e\u56de\u6536\u7684\u524d\u63d0\u4e0b\u5b58\u5728<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4f7f\u7528WeakMap\u53ef\u4ee5\u6709\u6548\u5730\u7ba1\u7406\u5185\u5b58\uff0c\u56e0\u4e3aWeakMap\u91cc\u7684\u952e\u503c\u5bf9\u4e0d\u4f1a\u963b\u6b62\u5783\u573e\u56de\u6536\u5668\u56de\u6536\u5b83\u4eec\u3002<\/p>\n<\/p>\n
\u56db\u3001\u4f7f\u7528\u89e3\u6784\u8d4b\u503c<\/h3>\n<\/p>\n
\u89e3\u6784\u8d4b\u503c\u662f\u53e6\u4e00\u79cd\u89e3\u9664\u5bf9\u8c61\u4e4b\u95f4\u5f15\u7528\u7684\u65b9\u6cd5\uff0c\u901a\u8fc7\u8fd9\u79cd\u65b9\u5f0f\u53ef\u4ee5\u521b\u5efa\u65b0\u7684\u53d8\u91cf\u6765\u5b58\u50a8\u503c\uff0c\u8fd9\u6837\u5c31\u4e0d\u4f1a\u6539\u53d8\u539f\u59cb\u5bf9\u8c61\u3002<\/p>\n<\/p>\n
let person = {<\/p>\n
    name: "John",<\/p>\n
    age: 30<\/p>\n
};<\/p>\n
\/\/ \u901a\u8fc7\u89e3\u6784\uff0c\u6211\u4eec\u521b\u5efa\u4e86\u4e24\u4e2a\u65b0\u7684\u53d8\u91cfname\u548cage<\/p>\n
let { name, age } = person;<\/p>\n
\/\/ \u6b64\u65f6\uff0cname\u548cage\u548c\u539f\u59cb\u7684person\u5bf9\u8c61\u6ca1\u6709\u5f15\u7528\u5173\u7cfb<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u89e3\u6784\u662f\u4e00\u79cd\u6d45\u62f7\u8d1d\uff0c\u53ea\u9002\u7528\u4e8e\u5bf9\u8c61\u7684\u9876\u5c42\u7ed3\u6784\u3002\u5982\u679c\u5bf9\u8c61\u5185\u90e8\u8fd8\u6709\u5d4c\u5957\u7684\u5bf9\u8c61\uff0c\u90a3\u4e48\u5d4c\u5957\u5bf9\u8c61\u4e4b\u95f4\u7684\u5f15\u7528\u5173\u7cfb\u4ecd\u4f1a\u4fdd\u7559\u3002<\/p>\n<\/p>\n
\u901a\u8fc7\u8fd9\u4e9b\u65b9\u6cd5\uff0c\u6211\u4eec\u53ef\u4ee5\u6709\u6548\u5730\u89e3\u9664JavaScript\u4e2d\u4e24\u4e2a\u5bf9\u8c61\u4e4b\u95f4\u7684\u5f15\u7528\uff0c\u6709\u52a9\u4e8e\u66f4\u597d\u5730\u7ba1\u7406\u5185\u5b58\u548c\u4f18\u5316\u7a0b\u5e8f\u6027\u80fd\u3002\u5728\u5177\u4f53\u7684\u7f16\u7a0b\u5b9e\u8df5\u4e2d\uff0c\u8981\u6839\u636e\u4e0d\u540c\u7684\u573a\u666f\u9009\u62e9\u6700\u5408\u9002\u7684\u65b9\u6cd5\u6765\u6253\u65ad\u5bf9\u8c61\u95f4\u7684\u5f15\u7528\u94fe\u6761\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
1. \u5982\u4f55\u5728JavaScript\u4e2d\u89e3\u9664\u4e24\u4e2a\u5bf9\u8c61\u4e4b\u95f4\u7684\u5f15\u7528\uff1f<\/strong>
\n\u5728JavaScript\u4e2d\uff0c\u8981\u89e3\u9664\u4e24\u4e2a\u5bf9\u8c61\u4e4b\u95f4\u7684\u5f15\u7528\uff0c\u53ef\u4ee5\u4f7f\u7528delete<\/code>\u64cd\u4f5c\u7b26\u5c06\u5bf9\u8c61\u7684\u5c5e\u6027\u8bbe\u7f6e\u4e3anull<\/code>\u6216undefined<\/code>\u3002\u4f8b\u5982\uff0c\u5982\u679c\u6709\u4e24\u4e2a\u5bf9\u8c61obj1<\/code>\u548cobj2<\/code>\uff0c\u5b83\u4eec\u4e92\u76f8\u5f15\u7528\u4e86\u5bf9\u65b9\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u4ee3\u7801\u89e3\u9664\u5f15\u7528\uff1a<\/p>\n
delete obj1.propertyName;\ndelete obj2.propertyName;\n<\/code><\/pre>\n
\u8fd9\u5c06\u4f7fobj1<\/code>\u548cobj2<\/code>\u4e4b\u95f4\u7684\u5f15\u7528\u65ad\u5f00\uff0c\u8ba9\u5b83\u4eec\u53ef\u4ee5\u88ab\u5783\u573e\u56de\u6536\u673a\u5236\u56de\u6536\u3002<\/p>\n
2. \u5728JavaScript\u4e2d\uff0c\u5982\u4f55\u907f\u514d\u5bf9\u8c61\u4e4b\u95f4\u7684\u5faa\u73af\u5f15\u7528\uff1f<\/strong>
\n\u5faa\u73af\u5f15\u7528\u662f\u6307\u4e24\u4e2a\u6216\u591a\u4e2a\u5bf9\u8c61\u4e4b\u95f4\u4e92\u76f8\u5f15\u7528\uff0c\u5f62\u6210\u4e00\u4e2a\u5faa\u73af\u94fe\u8868\uff0c\u5bfc\u81f4\u8fd9\u4e9b\u5bf9\u8c61\u65e0\u6cd5\u88ab\u5783\u573e\u56de\u6536\u3002\u4e3a\u4e86\u907f\u514d\u5faa\u73af\u5f15\u7528\uff0c\u53ef\u4ee5\u91c7\u53d6\u4ee5\u4e0b\u7b56\u7565\uff1a<\/p>\n
    \n
  • \u5c3d\u91cf\u907f\u514d\u5728\u5bf9\u8c61\u4e4b\u95f4\u76f8\u4e92\u5f15\u7528\uff0c\u5c3d\u91cf\u4f7f\u7528\u5355\u5411\u5f15\u7528\u3002<\/li>\n
  • \u5728\u4e0d\u9700\u8981\u4f7f\u7528\u5bf9\u8c61\u65f6\uff0c\u624b\u52a8\u5c06\u5176\u5f15\u7528\u7f6e\u4e3anull<\/code>\u6216undefined<\/code>\uff0c\u4ee5\u4fbf\u5783\u573e\u56de\u6536\u3002<\/li>\n
  • \u4f7f\u7528WeakMap\u6216WeakSet\u7b49JavaScript\u5185\u7f6e\u7684\u5f31\u5f15\u7528\u6570\u636e\u7ed3\u6784\uff0c\u8fd9\u4e9b\u6570\u636e\u7ed3\u6784\u4e0d\u4f1a\u963b\u6b62\u5bf9\u8c61\u88ab\u5783\u573e\u56de\u6536\u3002<\/li>\n<\/ul>\n
    3. \u5982\u4f55\u5224\u65ad\u4e24\u4e2a\u5bf9\u8c61\u662f\u5426\u76f8\u4e92\u5f15\u7528\uff1f<\/strong>
    \n\u5728JavaScript\u4e2d\uff0c\u8981\u5224\u65ad\u4e24\u4e2a\u5bf9\u8c61\u662f\u5426\u76f8\u4e92\u5f15\u7528\uff0c\u53ef\u4ee5\u4f7f\u7528\u9012\u5f52\u7b97\u6cd5\u904d\u5386\u5bf9\u8c61\u7684\u5c5e\u6027\uff0c\u5e76\u68c0\u67e5\u5c5e\u6027\u7684\u503c\u662f\u5426\u4e3a\u5bf9\u8c61\u7c7b\u578b\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u793a\u4f8b\u4ee3\u7801\uff1a<\/p>\n
    function areObjectsCyclic(obj1, obj2) {\n    var visited = new Set();\n\n    function traverse(obj) {\n        if (visited.has(obj))\n            return true;\n\n        visited.add(obj);\n        for (var prop in obj) {\n            if (typeof obj[prop] === 'object' && obj[prop] !== null) {\n                if (obj[prop] === obj1 || obj[prop] === obj2)\n                    return true;\n                \n                if (traverse(obj[prop]))\n                    return true;\n            }\n        }\n\n        return false;\n    }\n\n    return traverse(obj1) || traverse(obj2);\n}\n\nvar obj1 = { prop: {} };\nvar obj2 = { prop: obj1 };\nconsole.log(areObjectsCyclic(obj1, obj2)); \/\/ \u8f93\u51fa true\n<\/code><\/pre>\n
    \u4ee5\u4e0a\u4ee3\u7801\u5c06\u904d\u5386\u5bf9\u8c61\u7684\u5c5e\u6027\uff0c\u5e76\u4f7f\u7528Set\u6570\u636e\u7ed3\u6784\u5728\u904d\u5386\u8fc7\u7a0b\u4e2d\u8bb0\u5f55\u8bbf\u95ee\u8fc7\u7684\u5bf9\u8c61\u3002\u5982\u679c\u53d1\u73b0\u5c5e\u6027\u7684\u503c\u662f\u5bf9\u8c61\u4e14\u5df2\u7ecf\u8bbf\u95ee\u8fc7\uff0c\u8bf4\u660e\u5b58\u5728\u5faa\u73af\u5f15\u7528\u5173\u7cfb\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"JavaScript\u63d0\u4f9b\u4e86\u51e0\u79cd\u65b9\u6cd5\u6765\u89e3\u9664\u4e24\u4e2a\u5bf9\u8c61\u4e4b\u95f4\u7684\u5f15\u7528\uff0c\u5176\u4e2d\u5305\u62ec\u5c06\u5f15\u7528\u8bbe\u4e3anull\u3001\u4f7f\u7528WeakMap\u3001\u6df1 […]","protected":false},"author":3,"featured_media":169473,"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\/169463"}],"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=169463"}],"version-history":[{"count":0,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/169463\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/169473"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=169463"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=169463"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=169463"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}