{"id":3000,"date":"2020-07-31T13:42:58","date_gmt":"2020-07-31T05:42:58","guid":{"rendered":"http:\/\/www.yuguoxy.com\/geekhome\/?p=3000"},"modified":"2026-08-18T12:35:32","modified_gmt":"2026-08-18T04:35:32","slug":"%e5%9b%9e%e7%ad%94%e4%b8%80%e4%b8%8b%e8%bf%99-10-%e4%b8%aa%e6%9c%80%e5%b8%b8%e8%a7%81%e7%9a%84-javascript-%e9%97%ae%e9%a2%98","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=3000","title":{"rendered":"\u56de\u7b54\u4e00\u4e0b\u8fd9 10 \u4e2a\u6700\u5e38\u89c1\u7684 Javascript \u95ee\u9898"},"content":{"rendered":"
\n

\u4e0b\u9762\u6574\u7406\u4e86 JavaScript \u91cc\u6700\u5e38\u88ab\u95ee\u5230\u7684 10 \u4e2a\u95ee\u9898\u3002\u5b83\u4eec\u5927\u591a\u843d\u5728\u57fa\u7840\u4e0a\uff1a\u95ed\u5305<\/strong>\u3001Promise<\/strong>\u3001\u53d8\u91cf\u63d0\u5347<\/strong>\u3001\u7c7b<\/strong> \u7b49\u3002\u96be\u5ea6\u4e0d\u7b97\u9ad8\uff0c\u4f46\u9762\u8bd5\u91cc\u53cd\u590d\u51fa\u73b0\uff0c\u503c\u5f97\u4e00\u6b21\u5bf9\u9f50\u53e3\u5f84\u3002<\/p>\n

\u9002\u5408\u521a\u5f00\u59cb\u5b66 JS \u7684\u8bfb\u8005\uff1a\u5148\u770b\u61c2\u4f8b\u5b50\uff0c\u518d\u5bf9\u7167\u81ea\u5df1\u7684\u4ee3\u7801\u60f3\u4e00\u904d\u300c\u5982\u679c\u6539\u6389\u67d0\u4e00\u884c\u4f1a\u600e\u6837\u300d\u3002\u7b54\u6848\u4e0d\u662f\u552f\u4e00\u6807\u51c6\uff0c\u8fd9\u91cc\u662f\u4fbf\u4e8e\u8bb0\u5fc6\u7684\u8bb2\u6cd5\u3002<\/p>\n

\u539f\u6587\uff1ahttps:\/\/dev.to\/duomly\/10-most-common-javascript-questions-answered-1083<\/a>\u3002<\/p>\n

\u4e00\u3001\u95ed\u5305\u662f\u4ec0\u4e48<\/h2>\n

\u95ed\u5305\u662f\u300c\u51fd\u6570 bundled \u5728\u4e00\u8d77\u300d\u7684\u7ec4\u5408\uff1a\u5185\u90e8\u51fd\u6570\u53ef\u4ee5\u8bbf\u95ee\u81ea\u5df1\u7684\u53d8\u91cf\uff0c\u4e5f\u80fd\u8bbf\u95ee\u5916\u90e8\u51fd\u6570\u7684\u53d8\u91cf\u3002\u6700\u76f4\u767d\u7684\u529e\u6cd5\u662f\u770b\u4f8b\u5b50\uff1a<\/p>\n

function outer() {\n  var name = 'Maria';\n  function inner() {\n    console.log(name);\n  }\n  inner();\n}\nouter();\n\/\/ 'Maria'<\/code><\/pre>\n
inner()<\/code> \u80fd\u8bfb\u5230\u7236\u51fd\u6570\u91cc\u7684 name<\/code>\uff0c\u6240\u4ee5\u8c03\u7528 outer()<\/code> \u4f1a\u6253\u5370 Maria<\/code>\u3002\u5185\u90e8\u51fd\u6570\u4e5f\u80fd\u770b\u5230\u5916\u90e8\u7684\u53c2\u6570\u5bf9\u8c61\uff1b\u82e5\u5185\u5916\u5f62\u53c2\u540c\u540d\uff0c\u5185\u90e8\u4f1a\u76d6\u4f4f\u5916\u90e8\uff1a<\/p>\n
function outer(a, b) {\n  const inner = (a, b) => console.log(a, b);\n  inner(1, 2);\n}\nouter('Alice', 'Mark');\n\/\/ returns 1, 2<\/code><\/pre>\n
\u95ed\u5305\u6700\u5e38\u89c1\u7684\u7528\u9014\uff0c\u662f\u8ba9\u4e00\u4e2a\u51fd\u6570\u8fd4\u56de\u53e6\u4e00\u4e2a\u4ecd\u80fd\u300c\u8bb0\u4f4f\u300d\u5916\u5c42\u53d8\u91cf\u7684\u51fd\u6570\u3002<\/p>\n
\u4e8c\u3001DOM \u662f\u4ec0\u4e48<\/h2>\n
DOM \u662f\u6587\u6863\u5bf9\u8c61\u6a21\u578b\uff0c\u7f51\u7ad9\u7684\u9762\u5411\u5bf9\u8c61\u8868\u793a\uff0c\u53ef\u7528 JavaScript \u4fee\u6539\u989c\u8272\u3001\u4f4d\u7f6e\u3001\u5c3a\u5bf8\u7b49\u3002\u9009\u8282\u70b9\u5e38\u7528\uff1a<\/p>\n
    \n
  • \n
    getElementById()<\/code>\uff1a\u6309 id<\/code> \u53d6\u4e00\u4e2a\u5143\u7d20\uff1b<\/section>\n<\/li>\n
  • \n
    getElementsByName()<\/code>\uff1a\u6309 name<\/code> \u53d6\u8282\u70b9\u96c6\u5408\uff1b<\/section>\n<\/li>\n
  • \n
    getElementsByTagName()<\/code>\uff1a\u6309\u6807\u7b7e\u540d\u53d6\u96c6\u5408\uff1b<\/section>\n<\/li>\n
  • \n
    getElementsByClassName()<\/code>\uff1a\u6309\u7c7b\u540d\u53d6\u96c6\u5408\uff1b<\/section>\n<\/li>\n
  • \n
    querySelector()<\/code>\uff1a\u6309 CSS \u9009\u62e9\u5668\u53d6\u7b2c\u4e00\u4e2a\u5339\u914d\u3002<\/section>\n<\/li>\n<\/ul>\n
    \u6539\u7ed3\u6784\u65f6\u8fd8\u4f1a\u7528\u5230 appendChild()<\/code> \u6216\u5c5e\u6027 innerHTML<\/code>\uff08\u5b83\u662f\u5c5e\u6027\uff0c\u4e0d\u662f\u51fd\u6570\uff09\u3002<\/p>\n
    \u4e09\u3001Promise \u662f\u4ec0\u4e48<\/h2>\n
    Promise \u662f\u5f02\u6b65\u65b9\u6848\uff0c\u7528\u6765\u66ff\u4ee3\u5c42\u5c42\u56de\u8c03\u548c\u90e8\u5206\u4e8b\u4ef6\u5199\u6cd5\u3002ES6 \u628a\u5b83\u505a\u6210\u8bed\u8a00\u5185\u7f6e\u5bf9\u8c61\u3002\u4e24\u4e2a\u7279\u70b9\uff1a\u72b6\u6001\u4e0d\u53d7\u5916\u754c\u968f\u610f\u6539\u5199\uff1b\u4e00\u65e6\u4ece\u8fdb\u884c\u4e2d\u79bb\u5f00\uff0c\u5c31\u4e0d\u4f1a\u518d\u53d8\u3002<\/p>\n
    \u4e09\u79cd\u72b6\u6001\uff1aPending<\/strong>\uff08\u8fdb\u884c\u4e2d\uff09\u3001Fulfilled \/ Resolved<\/strong>\uff08\u6210\u529f\uff09\u3001Rejected<\/strong>\uff08\u5931\u8d25\uff09\u3002\u6210\u529f\u8d70 resolve<\/code> \u5e76\u8fdb\u5165 then()<\/code>\uff1b\u5931\u8d25\u8d70 reject<\/code> \u5e76\u8fdb\u5165 catch()<\/code>\u3002\u540c\u7c7b\u65b9\u6848\u8fd8\u6709 async\/await<\/code> \u548c\u56de\u8c03\u3002<\/p>\n
    \u56db\u3001\u539f\u578b\u662f\u4ec0\u4e48<\/h2>\n
    \u901a\u5e38\u6307 prototype<\/code>\uff08\u663e\u5f0f\u539f\u578b\uff09\u548c __proto__<\/code>\uff08\u9690\u5f0f\u539f\u578b\uff09\u3002\u5bf9\u8c61\u6cbf\u539f\u578b\u94fe\u7ee7\u627f\u65b9\u6cd5\u548c\u5c5e\u6027\uff0cObject.prototype<\/code> \u5728\u94fe\u9876\u3002\u7ed9\u6784\u9020\u51fd\u6570\u8865\u5145\u6210\u5458\u65f6\uff0c\u5199\u5728 Constructor.prototype<\/code> \u4e0a\uff1a<\/p>\n
    function Animal(name, kind, age) {\n  this.name = name;\n  this.kind = kind;\n  this.age = age;\n}\n\nAnimal.prototype.ownerName = 'Mark';<\/code><\/pre>\n
    \u8fd9\u6837\u6bcf\u4e2a new Animal(...)<\/code> \u5b9e\u4f8b\u90fd\u80fd\u987a\u7740\u539f\u578b\u8bfb\u5230 ownerName<\/code>\u3002\u539f\u6587\u5199\u6210 Animal.prototype.ownerName('Mark')<\/code> \u4f1a\u628a\u539f\u578b\u5f53\u51fd\u6570\u8c03\u7528\uff0c\u8fd0\u884c\u4f1a\u62a5\u9519\u3002<\/p>\n
    \u4e94\u3001\u53d8\u91cf\u63d0\u5347\u662f\u4ec0\u4e48<\/h2>\n
    \u63d0\u5347\uff08hoisting\uff09<\/strong> \u4f1a\u628a\u58f0\u660e\u63d0\u5230\u5f53\u524d\u4f5c\u7528\u57df\u9876\u90e8\uff1a\u51fd\u6570\u4f5c\u7528\u57df\u5185\u63d0\u5230\u51fd\u6570\u9876\uff0c\u5168\u5c40\u5219\u63d0\u5230\u5168\u5c40\u9876\u3002\u6240\u4ee5\u53ef\u4ee5\u300c\u5148\u7528\u540e\u58f0\u660e\u300dvar<\/code> \u53d8\u91cf\uff0c\u907f\u514d\u90e8\u5206 ReferenceError<\/code>\u3002<\/p>\n
    name = 'Ted';\nconsole.log(name);\nvar name;\n\/\/ 'Ted'\n\nvar name;\nname = 'Ted';\nconsole.log(name);\n\/\/ 'Ted'<\/code><\/pre>\n
    \u53ea\u7528 var<\/code> \u58f0\u660e\u3001\u5c1a\u672a\u8d4b\u503c\u65f6\uff0c\u503c\u662f undefined<\/code>\u3002let<\/code> \/ const<\/code> \u4e5f\u6709\u63d0\u5347\uff0c\u4f46\u5728\u521d\u59cb\u5316\u524d\u5904\u4e8e\u6682\u65f6\u6027\u6b7b\u533a\uff0c\u4e0d\u80fd\u63d0\u524d\u8bfb\u3002const<\/code> \u58f0\u660e\u65f6\u5fc5\u987b\u540c\u65f6\u521d\u59cb\u5316\u3002<\/p>\n
    \u516d\u3001\u5bf9\u8c61\u662f\u4ec0\u4e48<\/h2>\n
    \u5bf9\u8c61\u662f\u5e26\u5c5e\u6027\u548c\u65b9\u6cd5\u7684\u6570\u636e\u3002\u5b57\u7b26\u4e32\u3001\u6570\u503c\u3001\u6570\u7ec4\u3001\u51fd\u6570\u5728\u8bed\u8a00\u91cc\u90fd\u53ef\u4ee5\u6309\u5bf9\u8c61\u6765\u7528\u3002\u5c5e\u6027\u63cf\u8ff0\u7279\u5f81\uff08\u957f\u5ea6\u3001\u5bbd\u9ad8\uff09\uff0c\u65b9\u6cd5\u662f\u80fd\u6267\u884c\u7684\u52a8\u4f5c\uff08\u63d0\u4ea4\u8868\u5355\u3001\u53d6\u5e74\u4efd\uff09\u3002<\/p>\n
    var student = {\n  firstName: 'Alice',\n  lastName: 'Jones',\n  age: 21,\n  sayHi: function() {\n    return 'Hi, I am ' + this.firstName;\n  }\n}<\/code><\/pre>\n
    \u4e0a\u9762\u662f\u4e09\u4e2a\u5c5e\u6027\u52a0\u4e00\u4e2a\u65b9\u6cd5\u3002\u7bad\u5934\u51fd\u6570\u4e0d\u4f1a\u7ed1\u5b9a\u81ea\u5df1\u7684 this<\/code>\uff0c\u5199\u5728\u5bf9\u8c61\u5b57\u9762\u91cf\u91cc\u5f53\u65b9\u6cd5\u65f6\uff0cthis.firstName<\/code> \u5f80\u5f80\u4e0d\u662f\u4f60\u4ee5\u4e3a\u7684\u90a3\u4e2a\u5bf9\u8c61\uff0c\u6240\u4ee5\u8fd9\u91cc\u6539\u6210\u666e\u901a\u51fd\u6570\u3002<\/p>\n
    \u4e03\u3001\u51fd\u6570\u662f\u4ec0\u4e48<\/h2>\n
    \u51fd\u6570\u662f\u53ef\u88ab\u591a\u6b21\u8c03\u7528\u7684\u4ee3\u7801\u5757\uff0ctypeof<\/code> \u7ed3\u679c\u4e3a \"function\"<\/code>\u3002\u5b83\u4e5f\u6709\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u56e0\u6b64\u51fd\u6570\u4e5f\u662f\u5bf9\u8c61\u3002\u58f0\u660e\u6216\u8868\u8fbe\u5f0f\u90fd\u4ee5\u5173\u952e\u5b57 function<\/code> \u5f00\u5934\uff08\u7bad\u5934\u51fd\u6570\u9664\u5916\uff09\u3002\u5b9a\u4e49\u65f6\u62ec\u53f7\u91cc\u662f\u5f62\u53c2\uff0c\u8c03\u7528\u65f6\u4f20\u5165\u7684\u662f\u5b9e\u53c2\u3002<\/p>\n
    function calculate(x, y) {\n  return x * y;\n}\n\ncalculate(2, 5);<\/code><\/pre>\n
    \u516b\u3001\u7eaf\u51fd\u6570\u662f\u4ec0\u4e48<\/h2>\n
    \u76f8\u540c\u8f93\u5165\u6c38\u8fdc\u5f97\u5230\u76f8\u540c\u8f93\u51fa\uff0c\u4e14\u4e0d\u4f9d\u8d56\u3001\u4e0d\u4fee\u6539\u51fd\u6570\u5916\u90e8\u7684\u53ef\u89c2\u5bdf\u72b6\u6001\u3002\u50cf\u4e2d\u5b66\u51fd\u6570\uff1a\u4e00\u4e2a\u8f93\u5165\u53ea\u5bf9\u5e94\u4e00\u4e2a\u8f93\u51fa\uff1b\u4e0d\u540c\u8f93\u5165\u53ef\u4ee5\u649e\u4e0a\u540c\u4e00\u8f93\u51fa\uff0c\u4f46\u540c\u4e00\u8f93\u5165\u4e0d\u80fd\u7ed9\u51fa\u4e24\u4e2a\u7ed3\u679c\u3002<\/p>\n
      \n
    • \n
      \u76f8\u540c\u8f93\u5165 \u2192 \u76f8\u540c\u8f93\u51fa\uff1b<\/section>\n<\/li>\n
    • \n
      \u6ca1\u6709\u53ef\u89c2\u5bdf\u5230\u7684\u526f\u4f5c\u7528\u3002<\/section>\n<\/li>\n<\/ul>\n
      \u4e5d\u3001\u6784\u9020\u51fd\u6570\u662f\u4ec0\u4e48<\/h2>\n
      \u5728 JavaScript \u91cc\uff0c\u7528 new<\/code> \u8c03\u7528\u7684\u51fd\u6570\u90fd\u4f1a\u8d70\u6784\u9020\u8fc7\u7a0b\uff1a\u5185\u90e8 this<\/code> \u6307\u5411\u65b0\u5bf9\u8c61\uff0c\u65b0\u5bf9\u8c61\u7684\u539f\u578b\u6307\u5411\u6784\u9020\u51fd\u6570\u7684 prototype<\/code>\u3002\u82e5\u6ca1\u6709\u663e\u5f0f return<\/code> \u5bf9\u8c61\uff0c\u5c31\u9690\u5f0f\u8fd4\u56de\u8fd9\u4e2a this<\/code>\u3002<\/p>\n
      function Person(name, age) {\n  this.name = name;\n  this.age = age;\n}\n\nvar man = new Person('Mark', 23);\nconsole.log(man);\n\/\/ { name: 'Mark', age: 23 }<\/code><\/pre>\n
      \u539f\u6587\u7528\u7bad\u5934\u51fd\u6570\u5f53\u6784\u9020\u5668\u3002\u7bad\u5934\u51fd\u6570\u6ca1\u6709\u81ea\u5df1\u7684 this<\/code>\uff0c\u4e5f\u4e0d\u80fd\u88ab new<\/code>\uff0c\u8fd0\u884c\u4f1a TypeError\uff0c\u6240\u4ee5\u6539\u6210\u666e\u901a\u51fd\u6570\u3002<\/p>\n
      \u5341\u3001\u7c7b\u662f\u4ec0\u4e48<\/h2>\n
      ES6 \u8d77\u53ef\u4ee5\u7528 class<\/code> \u58f0\u660e\u7c7b\uff0c\u672c\u8d28\u4ecd\u662f\u51fd\u6570\u3002\u7c7b\u91cc\u8981\u6709 constructor()<\/code>\uff0c\u6bcf\u6b21 new<\/code> \u90fd\u4f1a\u8c03\u7528\uff0c\u5c5e\u6027\u5199\u5728\u6784\u9020\u91cc\u3002 \u7528 extends<\/code> \u57fa\u4e8e\u5df2\u6709\u7c7b\u6d3e\u751f\u3002React \u7684\u7c7b\u7ec4\u4ef6\u5c31\u662f\u5178\u578b\u7528\u6cd5\u3002<\/p>\n\n\n\n\n\n\n\n\n\n
      \u6982\u5ff5<\/th>\n\u4e00\u53e5\u8bdd<\/th>\n\u5bb9\u6613\u8e29\u7684\u5751<\/th>\n<\/tr>\n<\/thead>\n
      \u95ed\u5305<\/td>\n\u5185\u51fd\u6570\u8bb0\u4f4f\u5916\u5c42\u53d8\u91cf<\/td>\n\u5faa\u73af\u91cc\u7528 var \u7ed1\u5b9a\u65f6\u5bb9\u6613\u4e32\u503c<\/td>\n<\/tr>\n
      Promise<\/td>\n\u5f02\u6b65\u7684\u4e00\u6b21\u6027\u72b6\u6001\u673a<\/td>\n\u5df2\u6572\u5b9a\u7684\u72b6\u6001\u4e0d\u4f1a\u518d\u53d8<\/td>\n<\/tr>\n
      \u63d0\u5347<\/td>\nvar \/ \u51fd\u6570\u58f0\u660e\u4e0a\u79fb<\/td>\nlet\/const \u6709\u6682\u65f6\u6027\u6b7b\u533a<\/td>\n<\/tr>\n
      \u539f\u578b<\/td>\n\u5b9e\u4f8b\u6cbf\u94fe\u627e\u65b9\u6cd5\u548c\u5c5e\u6027<\/td>\n\u7ed9\u539f\u578b\u8d4b\u503c\u4e0d\u8981\u5199\u6210\u51fd\u6570\u8c03\u7528<\/td>\n<\/tr>\n
      \u6784\u9020 \/ \u7c7b<\/td>\nnew \u51fa\u6765\u7684\u5bf9\u8c61<\/td>\n\u4e0d\u8981\u7528\u7bad\u5934\u51fd\u6570\u5f53\u6784\u9020\u5668<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      \n
      \u4e00\u53e5\u8bdd\u603b\u7ed3\uff1a\u8fd9 10 \u95ee\u90fd\u56f4\u7740\u4f5c\u7528\u57df\u3001\u5f02\u6b65\u3001\u5bf9\u8c61\u6a21\u578b\u548c\u7c7b\u578b\u7cfb\u7edf\u8f6c\uff1a\u4f8b\u5b50\u80fd\u8dd1\u901a\uff0c\u53e3\u5f84\u624d\u80fd\u5728\u9762\u8bd5\u91cc\u7ad9\u5f97\u4f4f\u3002<\/strong><\/p>\n<\/blockquote>\n<\/section>\n","protected":false},"excerpt":{"rendered":"
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