{"id":168890,"date":"2024-05-08T16:33:30","date_gmt":"2024-05-08T08:33:30","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/168890.html"},"modified":"2024-05-08T16:33:34","modified_gmt":"2024-05-08T08:33:34","slug":"javascript-%e9%a1%b9%e7%9b%ae%e4%b8%ad%e7%9a%84-for-%e5%be%aa%e7%8e%af%e6%9c%89%e5%93%aa%e4%ba%9b%e7%94%a8%e5%a4%84","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/168890.html","title":{"rendered":"JavaScript \u9879\u76ee\u4e2d\u7684 for \u5faa\u73af\u6709\u54ea\u4e9b\u7528\u5904"},"content":{"rendered":"

\"JavaScript<\/p>\n

\u5728JavaScript\u9879\u76ee\u4e2d\uff0cfor\u5faa\u73af<\/strong>\u7684\u7528\u5904\u5e7f\u6cdb\uff0c\u65e2\u53ef\u4ee5\u904d\u5386\u6570\u7ec4\u3001\u5bf9\u8c61\uff0c\u4e5f\u53ef\u4ee5\u5904\u7406\u5f02\u6b65\u4efb\u52a1\u961f\u5217\u3001\u8fdb\u884c\u6027\u80fd\u4f18\u5316\u3002\u5176\u4e2d\uff0c\u904d\u5386\u6570\u7ec4\u662f\u5176\u6700\u5e38\u89c1\u7684\u5e94\u7528\u4e4b\u4e00\u3002<\/p>\n<\/p>\n

\u904d\u5386\u6570\u7ec4\u65f6\uff0cfor\u5faa\u73af\u80fd\u6309\u987a\u5e8f\u8bbf\u95ee\u6570\u7ec4\u7684\u6bcf\u4e2a\u5143\u7d20<\/strong>\uff0c\u8fdb\u884c\u8bfb\u53d6\u6216\u8d4b\u503c\u64cd\u4f5c\u3002\u8fd9\u5bf9\u4e8e\u5904\u7406\u6570\u636e\u96c6\u5408\u3001\u5b9e\u73b0\u590d\u6742\u7684\u6570\u5b66\u8ba1\u7b97\u7b49\u573a\u666f\u5c24\u4e3a\u91cd\u8981\u3002\u901a\u8fc7\u8bbe\u7f6e\u5faa\u73af\u8d77\u59cb\u6761\u4ef6\u3001\u7ec8\u6b62\u6761\u4ef6\u548c\u8fed\u4ee3\u6b65\u957f\uff0c\u5f00\u53d1\u8005\u53ef\u4ee5\u7075\u6d3b\u5730\u63a7\u5236\u904d\u5386\u8fc7\u7a0b\uff0c\u8fdb\u800c\u5b9e\u73b0\u5bf9\u6570\u7ec4\u7684\u7cbe\u786e\u64cd\u4f5c\u3002<\/p>\n<\/p>\n

\u4e00\u3001\u6570\u7ec4\u904d\u5386<\/strong><\/h3>\n<\/p>\n

\u6570\u7ec4\u904d\u5386\u662f\u6700\u57fa\u672c\u7684\u5e94\u7528\u573a\u666f\u4e4b\u4e00\u3002for\u5faa\u73af\u901a\u8fc7\u8fed\u4ee3\u6570\u7ec4\u7d22\u5f15\uff0c\u4f7f\u5f97\u5f00\u53d1\u8005\u80fd\u5bf9\u6bcf\u4e2a\u6570\u7ec4\u5143\u7d20\u6267\u884c\u7279\u5b9a\u7684\u64cd\u4f5c\u3002<\/p>\n<\/p>\n

\u793a\u4f8b\u4ee3\u7801<\/h4>\n<\/p>\n

const array = [1, 2, 3, 4, 5];<\/p>\n
for (let i = 0; i < array.length; i++) {<\/p>\n
    console.log(array[i]);<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u6bb5\u4ee3\u7801\u9010\u4e2a\u8f93\u51fa\u6570\u7ec4\u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\u3002\u5b83\u7684\u5de5\u4f5c\u539f\u7406\u5728\u4e8e\uff0c\u8bbe\u7f6e\u5faa\u73af\u53d8\u91cfi<\/code>\u4ece0\u5f00\u59cb\uff0c\u76f4\u5230i<\/code>\u5c0f\u4e8e\u6570\u7ec4array<\/code>\u7684\u957f\u5ea6\uff0c\u6bcf\u6b21\u5faa\u73afi<\/code>\u90fd\u4f1a\u589e\u52a01\uff0c\u4ece\u800c\u9010\u6b65\u8bbf\u95ee\u6570\u7ec4\u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\u3002<\/p>\n<\/p>\n
\u4f7f\u7528\u573a\u666f<\/h4>\n<\/p>\n
\u5728\u5904\u7406\u4e00\u7ec4\u6570\u636e\u65f6\uff0c\u7ecf\u5e38\u9700\u8981\u904d\u5386\u6570\u7ec4\u8fdb\u884c\u7edf\u8ba1\u5206\u6790\u3001\u6570\u636e\u52a0\u5de5\u7b49\u4efb\u52a1\u3002\u4f8b\u5982\uff0c\u8ba1\u7b97\u6570\u7ec4\u4e2d\u6240\u6709\u5143\u7d20\u7684\u603b\u548c\u3001\u7b5b\u9009\u7b26\u5408\u7279\u5b9a\u6761\u4ef6\u7684\u5143\u7d20\u96c6\u5408\u7b49\u3002<\/p>\n<\/p>\n
\u4e8c\u3001\u5faa\u73af\u904d\u5386\u5bf9\u8c61<\/strong><\/h3>\n<\/p>\n
\u5728JavaScript\u4e2d\uff0c\u5bf9\u8c61\u662f\u4e00\u79cd\u590d\u6742\u7684\u6570\u636e\u7ed3\u6784\uff0cfor\u5faa\u73af\u53ef\u4ee5\u7528\u6765\u904d\u5386\u5bf9\u8c61\u7684\u5c5e\u6027\uff0c\u4ece\u800c\u5b9e\u73b0\u5bf9\u5bf9\u8c61\u4e2d\u6570\u636e\u7684\u5904\u7406\u3002<\/p>\n<\/p>\n
\u793a\u4f8b\u4ee3\u7801<\/h4>\n<\/p>\n
const person = {<\/p>\n
    name: "John",<\/p>\n
    age: 30,<\/p>\n
    occupation: "Developer"<\/p>\n
};<\/p>\n
for (const key in person) {<\/p>\n
    console.log(`${key}: ${person[key]}`);<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u4e2a\u4f8b\u5b50\u901a\u8fc7for-in<\/code>\u5faa\u73af\u904d\u5386\u5bf9\u8c61person<\/code>\u7684\u6bcf\u4e2a\u5c5e\u6027\uff0c\u5e76\u8f93\u51fa\u5c5e\u6027\u540d\u53ca\u5176\u5bf9\u5e94\u7684\u503c\u3002\u8fd9\u6837\u7684\u64cd\u4f5c\u9002\u7528\u4e8e\u5bf9\u8c61\u5c5e\u6027\u7684\u8bfb\u53d6\u3001\u4fee\u6539\u6216\u5176\u4ed6\u5904\u7406\u3002<\/p>\n<\/p>\n
\u4f7f\u7528\u573a\u666f<\/h4>\n<\/p>\n
\u5728\u9700\u8981\u52a8\u6001\u5904\u7406\u5bf9\u8c61\u5c5e\u6027\u3001\u8fdb\u884c\u914d\u7f6e\u9879\u7ba1\u7406\u6216\u72b6\u6001\u8ddf\u8e2a\u65f6\uff0c\u904d\u5386\u5bf9\u8c61\u5c5e\u6027\u662f\u4e00\u79cd\u5e38\u7528\u7684\u65b9\u6cd5\u3002<\/p>\n<\/p>\n
\u4e09\u3001\u5f02\u6b65\u4efb\u52a1\u5904\u7406<\/strong><\/h3>\n<\/p>\n
\u5728\u73b0\u4ee3JavaScript\u5f00\u53d1\u4e2d\uff0c\u5904\u7406\u5f02\u6b65\u4efb\u52a1\u662f\u5e38\u89c1\u9700\u6c42\u3002for\u5faa\u73af\u7ed3\u5408async\/awAI<\/a>t<\/code>\u53ef\u4ee5\u6709\u6548\u63a7\u5236\u5f02\u6b65\u4efb\u52a1\u7684\u987a\u5e8f\u6267\u884c\u3002<\/p>\n<\/p>\n
\u793a\u4f8b\u4ee3\u7801<\/h4>\n<\/p>\n
const fetchSomething = async () => {<\/p>\n
    \/\/ \u5047\u8bbe\u8fd9\u662f\u4e00\u4e2a\u8fd4\u56dePromise\u7684\u5f02\u6b65\u51fd\u6570<\/p>\n
};<\/p>\n
const tasks = [fetchSomething, fetchSomething, fetchSomething];<\/p>\n
(async () => {<\/p>\n
    for (let task of tasks) {<\/p>\n
        await task();<\/p>\n
    }<\/p>\n
})();<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u6bb5\u4ee3\u7801\u6f14\u793a\u4e86\u5982\u4f55\u4f7f\u7528for\u5faa\u73af\u987a\u5e8f\u5904\u7406\u4e00\u4e2a\u5f02\u6b65\u4efb\u52a1\u961f\u5217\u3002\u6bcf\u4e2a\u4efb\u52a1\u90fd\u88ab\u7b49\u5f85\u6267\u884c\u5b8c\u6210\uff0c\u7136\u540e\u518d\u6267\u884c\u4e0b\u4e00\u4e2a\uff0c\u8fd9\u5bf9\u4e8e\u4f9d\u8d56\u524d\u4e00\u4e2a\u4efb\u52a1\u7ed3\u679c\u7684\u5f02\u6b65\u64cd\u4f5c\u975e\u5e38\u91cd\u8981\u3002<\/p>\n<\/p>\n
\u4f7f\u7528\u573a\u666f<\/h4>\n<\/p>\n
\u5728\u9700\u8981\u6309\u987a\u5e8f\u5904\u7406\u591a\u4e2a\u7f51\u7edc\u8bf7\u6c42\u3001\u6570\u636e\u5e93\u64cd\u4f5c\u7b49\u5f02\u6b65\u4efb\u52a1\u65f6\uff0c\u8fd9\u79cd\u6a21\u5f0f\u975e\u5e38\u6709\u7528\u3002<\/p>\n<\/p>\n
\u56db\u3001\u6027\u80fd\u4f18\u5316<\/strong><\/h3>\n<\/p>\n
\u5c3d\u7ba1\u73b0\u4ee3JavaScript\u5f15\u64ce\u5bf9\u4e8e\u5faa\u73af\u7684\u4f18\u5316\u5df2\u7ecf\u975e\u5e38\u9ad8\u6548\uff0c\u4f46\u5728\u5904\u7406\u5927\u91cf\u6570\u636e\u6216\u5728\u5173\u952e\u4ee3\u7801\u8def\u5f84\u4e2d\uff0cfor\u5faa\u73af\u7684\u6027\u80fd\u8fd8\u662f\u9700\u8981\u5173\u6ce8\u7684\u3002<\/p>\n<\/p>\n
\u5185\u8054\u53d8\u91cf\u548c\u6761\u4ef6\u5224\u65ad\u4f18\u5316<\/h4>\n<\/p>\n
\u901a\u8fc7\u51cf\u5c11\u5faa\u73af\u4e2d\u6bcf\u6b21\u8fed\u4ee3\u7684\u8ba1\u7b97\u91cf\uff0c\u53ef\u4ee5\u663e\u8457\u63d0\u9ad8\u5faa\u73af\u7684\u5904\u7406\u901f\u5ea6\u3002\u4f8b\u5982\uff0c\u901a\u8fc7\u5185\u8054\u53d8\u91cf\u3001\u51cf\u5c11\u6761\u4ef6\u5224\u65ad\u7b49\u624b\u6bb5\u6765\u63d0\u5347\u6027\u80fd\u3002<\/p>\n<\/p>\n
\u4f7f\u7528\u573a\u666f<\/h4>\n<\/p>\n
\u5728\u6e38\u620f\u5f00\u53d1\u3001\u6570\u636e\u5904\u7406\u7b49\u5bf9\u6027\u80fd\u6709\u8f83\u9ad8\u8981\u6c42\u7684\u573a\u666f\u4e2d\uff0c\u5bf9for\u5faa\u73af\u7684\u4f18\u5316\u5c24\u4e3a\u91cd\u8981\u3002<\/p>\n<\/p>\n
\u4e94\u3001\u5c0f\u7ed3<\/strong><\/h3>\n<\/p>\n
for\u5faa\u73af<\/strong>\u5728JavaScript\u9879\u76ee\u4e2d\u626e\u6f14\u7740\u975e\u5e38\u91cd\u8981\u7684\u89d2\u8272\u3002\u65e0\u8bba\u662f\u5904\u7406\u6570\u7ec4\u3001\u5bf9\u8c61\uff0c\u8fd8\u662f\u6267\u884c\u5f02\u6b65\u4efb\u52a1\uff0cfor\u5faa\u73af\u90fd\u63d0\u4f9b\u4e86\u4e00\u79cd\u7075\u6d3b\u4e14\u9ad8\u6548\u7684\u65b9\u5f0f\u6765\u5904\u7406\u5404\u79cd\u4efb\u52a1\u3002\u7406\u89e3\u5e76\u638c\u63e1for\u5faa\u73af\u7684\u591a\u6837\u7528\u9014\uff0c\u5bf9\u4e8e\u6bcf\u4e00\u4f4dJavaScript\u5f00\u53d1\u8005\u6765\u8bf4\u90fd\u975e\u5e38\u5fc5\u8981\u3002\u901a\u8fc7\u7ed3\u5408\u5b9e\u9645\u7684\u9879\u76ee\u9700\u6c42\uff0c\u9009\u62e9\u5408\u9002\u7684\u5faa\u73af\u7b56\u7565\u548c\u4f18\u5316\u624b\u6bb5\uff0c\u53ef\u4ee5\u4f7f\u4ee3\u7801\u66f4\u52a0\u9ad8\u6548\u3001\u53ef\u7ef4\u62a4\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
Q1\uff1a\u5982\u4f55\u5728 JavaScript \u9879\u76ee\u4e2d\u4f7f\u7528 for \u5faa\u73af\uff1f<\/strong><\/p>\n
\u5728 JavaScript \u9879\u76ee\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 for \u5faa\u73af\u6765\u91cd\u590d\u6267\u884c\u4e00\u6bb5\u4ee3\u7801\u3002\u4f7f\u7528 for \u5faa\u73af\u7684\u8bed\u6cd5\u662f\uff1afor (\u521d\u59cb\u6761\u4ef6; \u7ec8\u6b62\u6761\u4ef6; \u8fed\u4ee3\u5668) {\u4ee3\u7801\u5757}<\/code>\u3002\u901a\u8fc7\u521d\u59cb\u5316\u6761\u4ef6\uff0c\u6307\u5b9a\u5faa\u73af\u7684\u8d77\u59cb\u70b9\uff1b\u901a\u8fc7\u7ec8\u6b62\u6761\u4ef6\uff0c\u786e\u5b9a\u5faa\u73af\u4f55\u65f6\u7ed3\u675f\uff1b\u901a\u8fc7\u8fed\u4ee3\u5668\uff0c\u63a7\u5236\u6bcf\u6b21\u5faa\u73af\u6267\u884c\u540e\u7684\u64cd\u4f5c\u3002\u8fd9\u6837\u53ef\u4ee5\u5728 JavaScript \u9879\u76ee\u4e2d\u5b9e\u73b0\u8bf8\u5982\u904d\u5386\u6570\u7ec4\u3001\u8fed\u4ee3\u5bf9\u8c61\u3001\u6267\u884c\u6307\u5b9a\u6b21\u6570\u7684\u64cd\u4f5c\u7b49\u7b49\u3002<\/p>\n
Q2\uff1a\u5982\u4f55\u5728 JavaScript \u9879\u76ee\u4e2d\u904d\u5386\u6570\u7ec4\uff1f<\/strong><\/p>\n
\u901a\u8fc7\u4f7f\u7528 for \u5faa\u73af\uff0c\u6211\u4eec\u53ef\u4ee5\u8f7b\u677e\u5730\u904d\u5386 JavaScript \u9879\u76ee\u4e2d\u7684\u6570\u7ec4\u3002\u4f8b\u5982\uff0c\u53ef\u4ee5\u4f7f\u7528 for \u5faa\u73af\u6765\u8bbf\u95ee\u6570\u7ec4\u7684\u6bcf\u4e2a\u5143\u7d20\uff0c\u5e76\u5bf9\u5176\u8fdb\u884c\u76f8\u5e94\u7684\u64cd\u4f5c\u3002\u5728\u5faa\u73af\u7684\u6bcf\u4e00\u6b21\u8fed\u4ee3\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u8fed\u4ee3\u5668\u6765\u9010\u4e2a\u8bbf\u95ee\u6570\u7ec4\u7684\u5143\u7d20\u3002\u8fd9\u6837\uff0c\u6211\u4eec\u53ef\u4ee5\u5728 JavaScript \u9879\u76ee\u4e2d\u5b9e\u73b0\u6570\u7ec4\u7684\u904d\u5386\u3001\u67e5\u627e\u7279\u5b9a\u503c\u3001\u8ba1\u7b97\u6570\u7ec4\u603b\u548c\u7b49\u64cd\u4f5c\u3002<\/p>\n
Q3\uff1a\u5982\u4f55\u5728 JavaScript \u9879\u76ee\u4e2d\u8fed\u4ee3\u5bf9\u8c61\u5c5e\u6027\uff1f<\/strong><\/p>\n
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