{"id":86,"date":"2026-09-01T01:23:53","date_gmt":"2026-08-31T17:23:53","guid":{"rendered":"https:\/\/www.ziliaochi.cn\/index.php\/2026\/09\/01\/interview-javascript-core-questions\/"},"modified":"2026-09-02T00:40:57","modified_gmt":"2026-09-01T16:40:57","slug":"interview-javascript-core-questions","status":"publish","type":"post","link":"https:\/\/www.ziliaochi.cn\/index.php\/2026\/09\/01\/interview-javascript-core-questions\/","title":{"rendered":"JavaScript \u9762\u8bd5\u786c\u9898\uff1a\u4e8b\u4ef6\u5faa\u73af\u3001\u95ed\u5305\u3001\u539f\u578b\u4e0e this \u7684 15 \u9053\u8ffd\u95ee"},"content":{"rendered":"
\n
\u5173\u952e\u8bcd<\/span>\u4e8b\u4ef6\u5faa\u73af\u3001\u5b8f\u4efb\u52a1\u3001\u5fae\u4efb\u52a1\u3001\u95ed\u5305\u3001\u539f\u578b\u94fe\u3001this\u3001Promise<\/div>\n
\n
\u76ee\u5f55<\/div>\n
    \n
  1. \u4e00\u3001\u4e8b\u4ef6\u5faa\u73af\uff1a\u5148\u5206\u6e05\u4e24\u4e2a\u961f\u5217<\/a><\/li>\n
  2. \u4e8c\u3001\u95ed\u5305\uff1a\u4e0d\u6b62\u662f”\u51fd\u6570\u5957\u51fd\u6570”<\/a><\/li>\n
  3. \u4e09\u3001\u539f\u578b\u4e0e\u7ee7\u627f\uff1a\u628a\u4e09\u5f20\u5173\u7cfb\u56fe\u8bb0\u7262<\/a><\/li>\n
  4. \u56db\u3001this\uff1a\u56db\u79cd\u7ed1\u5b9a\u89c4\u5219\u7684\u4f18\u5148\u7ea7<\/a><\/li>\n
  5. \u4e94\u3001\u7efc\u5408\u9898\uff1a\u628a\u56db\u4e2a\u77e5\u8bc6\u70b9\u4e32\u8d77\u6765<\/a><\/li>\n
  6. \u516d\u3001\u5c0f\u7ed3<\/a><\/li>\n<\/ol>\n<\/div>\n

    \u4e8b\u4ef6\u5faa\u73af\u3001\u95ed\u5305\u3001\u539f\u578b\u3001this\u2014\u2014JavaScript \u9762\u8bd5\u7684”\u56db\u5927\u540d\u6355”\u3002\u5b83\u4eec\u4e4b\u6240\u4ee5\u5e38\u8003\uff0c\u4e0d\u662f\u56e0\u4e3a\u504f\uff0c\u800c\u662f\u56e0\u4e3a\u8fd9\u56db\u5757\u76f4\u63a5\u51b3\u5b9a\u4e86\u4f60\u5199\u7684\u5f02\u6b65\u4ee3\u7801\u4f1a\u4e0d\u4f1a\u51fa\u8be1\u5f02 bug<\/strong>\u3002<\/p>\n

    \u672c\u6587\u7528 15 \u9053\u9012\u8fdb\u5f0f\u9898\u76ee\uff0c\u628a\u6bcf\u4e2a\u6982\u5ff5\u7684\u5e38\u89c1\u8bef\u89e3\u4e0e\u8ffd\u95ee\u9677\u9631<\/strong>\u4e00\u6b21\u8bb2\u900f\u3002<\/p>\n

    \u4e00\u3001\u4e8b\u4ef6\u5faa\u73af\uff1a\u5148\u5206\u6e05\u4e24\u4e2a\u961f\u5217<\/h2>\n
    \"\u4e00\u6b21\u4e8b\u4ef6\u5faa\u73af\u7684\u6267\u884c\u987a\u5e8f\"
    \u4e8b\u4ef6\u5faa\u73af\uff1a\u6267\u884c\u4e00\u4e2a\u5b8f\u4efb\u52a1 \u2192 \u6e05\u7a7a\u6240\u6709\u5fae\u4efb\u52a1 \u2192 \u6e32\u67d3 \u2192 \u4e0b\u4e00\u4e2a\u5b8f\u4efb\u52a1<\/figcaption><\/figure>\n

    Q1\uff1a\u5b8f\u4efb\u52a1\u548c\u5fae\u4efb\u52a1\u7684\u6267\u884c\u987a\u5e8f\u662f\u600e\u6837\u7684\uff1f<\/strong>
    \n\u4e00\u6b21\u4e8b\u4ef6\u5faa\u73af\uff1a\u6267\u884c\u4e00\u4e2a\u5b8f\u4efb\u52a1 \u2192 \u6e05\u7a7a\u6240\u6709\u5fae\u4efb\u52a1 \u2192 \uff08\u53ef\u80fd\uff09\u6e32\u67d3 \u2192 \u53d6\u4e0b\u4e00\u4e2a\u5b8f\u4efb\u52a1<\/strong>\u3002\u5173\u952e\u662f\u5fae\u4efb\u52a1\u4f1a\u88ab\u4e00\u6b21\u6027\u6e05\u7a7a<\/strong>\uff0c\u800c\u4e0d\u662f\u6bcf\u6b21\u53ea\u53d6\u4e00\u4e2a\u3002<\/p>\n

    console.log('1')\n\nsetTimeout(() => console.log('2'), 0)\n\nPromise.resolve().then(() => console.log('3'))\n  .then(() => console.log('4'))\n\nconsole.log('5')\n\n\/\/ \u8f93\u51fa\uff1a1 5 3 4 2\n<\/code><\/pre>\n
    \u89e3\u91ca\uff1a\u540c\u6b65\u4ee3\u7801\u8f93\u51fa 1\u30015\uff1b\u7136\u540e\u6e05\u7a7a\u5fae\u4efb\u52a1\u961f\u5217\uff0c\u94fe\u5f0f then \u4ea7\u751f\u7684 3 \u548c 4 \u90fd\u5728\u540c\u4e00\u8f6e\u6e05\u7a7a<\/strong>\uff1b\u6700\u540e\u6267\u884c\u5b8f\u4efb\u52a1 setTimeout\uff0c\u8f93\u51fa 2\u3002<\/p>\n
    Q2\uff1a\u5fae\u4efb\u52a1\u91cc\u518d\u4ea7\u751f\u5fae\u4efb\u52a1\u4f1a\u600e\u6837\uff1f<\/strong>
    \n\u4f1a\u5728\u672c\u8f6e\u7ee7\u7eed\u88ab\u6267\u884c<\/strong>\uff0c\u76f4\u5230\u961f\u5217\u4e3a\u7a7a\u3002\u8fd9\u610f\u5473\u7740\u9012\u5f52\u4ea7\u751f\u5fae\u4efb\u52a1\u4f1a\u997f\u6b7b\u5b8f\u4efb\u52a1<\/strong>\uff0c\u9875\u9762\u5361\u6b7b\u3002\u8fd9\u662f\u9762\u8bd5\u91cc\u533a\u5206”\u80cc\u8fc7”\u548c”\u61c2\u4e86”\u7684\u5173\u952e\u8ffd\u95ee\u3002<\/p>\n
    Q3\uff1aasync\/await<\/code> \u5728\u4e8b\u4ef6\u5faa\u73af\u91cc\u600e\u4e48\u7b97\uff1f<\/strong>
    \nawait<\/code> \u540e\u9762\u7684\u4ee3\u7801\u76f8\u5f53\u4e8e\u653e\u8fdb .then()<\/code> \u91cc\uff0c\u5c5e\u4e8e\u5fae\u4efb\u52a1\u3002\u4f46\u8981\u6ce8\u610f\uff1a\u591a\u4e2a await<\/code> \u4e32\u8054\u4f1a\u4ea7\u751f\u591a\u8f6e\u5fae\u4efb\u52a1<\/strong>\uff0c\u987a\u5e8f\u9898\u91cc\u6700\u5bb9\u6613\u9519\u5728\u8fd9\u91cc\u3002<\/p>\n
    Q4\uff1aNode.js \u548c\u6d4f\u89c8\u5668\u7684\u4e8b\u4ef6\u5faa\u73af\u4e00\u6837\u5417\uff1f<\/strong>
    \n\u4e0d\u4e00\u6837\u3002Node \u6709\u66f4\u7ec6\u7684\u9636\u6bb5\u5212\u5206\uff08timers\u3001poll\u3001check \u7b49\uff09\uff0c\u4e14\u6709 process.nextTick<\/code>\uff0c\u5176\u4f18\u5148\u7ea7\u9ad8\u4e8e\u666e\u901a\u5fae\u4efb\u52a1<\/strong>\u3002\u7b54”\u5b8c\u5168\u4e00\u6837”\u662f\u5e38\u89c1\u5931\u5206\u70b9\u3002<\/p>\n
    \u4e8c\u3001\u95ed\u5305\uff1a\u4e0d\u6b62\u662f”\u51fd\u6570\u5957\u51fd\u6570”<\/h2>\n
    Q5\uff1a\u95ed\u5305\u5230\u5e95\u662f\u4ec0\u4e48\uff1f<\/strong>
    \n\u95ed\u5305\u662f\u51fd\u6570\u4e0e\u5176\u5b9a\u4e49\u65f6\u6240\u5728\u8bcd\u6cd5\u73af\u5883\u7684\u7ec4\u5408<\/strong>\u3002\u53ea\u8981\u5185\u90e8\u51fd\u6570\u6301\u6709\u5bf9\u5916\u90e8\u53d8\u91cf\u7684\u5f15\u7528\uff0c\u4e14\u8be5\u51fd\u6570\u5728\u5176\u8bcd\u6cd5\u4f5c\u7528\u57df\u4e4b\u5916\u88ab\u8c03\u7528\uff0c\u95ed\u5305\u5c31\u4ea7\u751f\u4e86\u3002<\/p>\n
    Q6\uff1a\u7ecf\u5178\u9677\u9631\u9898\u2014\u2014\u5faa\u73af\u91cc\u7684\u95ed\u5305\u3002<\/strong><\/p>\n
    for (var i = 0; i < 3; i++) {\n  setTimeout(() => console.log(i), 0)\n}\n\/\/ \u8f93\u51fa\uff1a3 3 3\uff08var \u662f\u51fd\u6570\u4f5c\u7528\u57df\uff0c\u5171\u4eab\u540c\u4e00\u4e2a i\uff09\n\nfor (let i = 0; i < 3; i++) {\n  setTimeout(() => console.log(i), 0)\n}\n\/\/ \u8f93\u51fa\uff1a0 1 2\uff08let \u4e3a\u6bcf\u6b21\u8fed\u4ee3\u521b\u5efa\u65b0\u7684\u7ed1\u5b9a\uff09\n<\/code><\/pre>\n
    \u8ffd\u95ee\uff1a<\/strong>“\u4e0d\u7528 let \u600e\u4e48\u4fee\uff1f” \u2192 \u7528 IIFE \u521b\u5efa\u65b0\u7684\u51fd\u6570\u4f5c\u7528\u57df\uff0c\u6216\u7528 setTimeout<\/code> \u7684\u7b2c\u4e09\u4e2a\u53c2\u6570\u4f20\u503c\u3002<\/p>\n
    Q7\uff1a\u95ed\u5305\u4f1a\u5bfc\u81f4\u5185\u5b58\u6cc4\u6f0f\u5417\uff1f<\/strong>
    \n\u95ed\u5305\u672c\u8eab\u4e0d\u4f1a”\u6cc4\u6f0f”\uff0c\u5b83\u53ea\u662f\u8ba9\u53d8\u91cf\u65e0\u6cd5\u88ab\u56de\u6536<\/strong>\u3002\u771f\u6b63\u7684\u95ee\u9898\u662f\u88ab\u95ed\u5305\u6301\u6709\u7684\u5927\u5bf9\u8c61\uff08\u5982\u6574\u4e2a DOM \u5b50\u6811\u3001\u7f13\u5b58\u6570\u7ec4\uff09\u4e00\u76f4\u4e0d\u88ab\u91ca\u653e\u3002\u89e3\u6cd5\u662f\u89e3\u9664\u5f15\u7528\u6216\u7f29\u5c0f\u6355\u83b7\u8303\u56f4<\/strong>\uff0c\u800c\u4e0d\u662f\u4e0d\u7528\u95ed\u5305\u3002<\/p>\n
    \u4e09\u3001\u539f\u578b\u4e0e\u7ee7\u627f\uff1a\u628a\u4e09\u5f20\u5173\u7cfb\u56fe\u8bb0\u7262<\/h2>\n
    Q8\uff1a__proto__<\/code> \u548c prototype<\/code> \u7684\u533a\u522b\uff1f<\/strong><\/p>\n