{"id":2311,"date":"2023-02-13T03:00:25","date_gmt":"2023-02-12T19:00:25","guid":{"rendered":"https:\/\/www.lcettsg.cn\/code\/?p=2311"},"modified":"2023-03-05T14:49:30","modified_gmt":"2023-03-05T06:49:30","slug":"javascript%e5%ad%a6%e4%b9%a0%e7%ac%94%e8%ae%b0","status":"publish","type":"post","link":"https:\/\/www.lcettsg.cn\/code\/?p=2311","title":{"rendered":"javascript\u5b66\u4e60\u7b14\u8bb0"},"content":{"rendered":"\n

\u5bf9\u8c61<\/h2>\n\n\n\n

Object.keys(); <\/p>\n\n\n\n

delete person.name; \/\/\u5220\u9664\u5bf9\u8c61\u4e2d\u7684\u4e00\u4e2a\u5c5e\u6027<\/p>\n\n\n\n

\u679a\u4e3e\u5bf9\u8c61\u5c5e\u6027\uff1a
for … in\u8bed\u53e5\uff1a<\/p>\n\n\n\n

for(var \u53d8\u91cf in \u5bf9\u8c61\uff09{<\/p>\n\n\n\n

}<\/p>\n\n\n\n

\u5168\u5c40\u4f5c\u7528\u57df\uff1a\u6307\u4e00\u4e2a\u53d8\u91cf\u7684\u4f5c\u7528\u8303\u56f4\u3002JS\u4e2d\u4e00\u5171\u6709\u4e24\u79cd\u4f5c\u7528\u57df\uff0c\u5168\u5c40\u4f5c\u7528\u57df\u548c\u51fd\u6570\u4f5c\u7528\u57df\u3002
\u76f4\u63a5\u7f16\u5199\u5728script\u6807\u7b7e\u4e2d\u7684JS\u4ee3\u7801\uff0c\u90fd\u5728\u5168\u5c40\u4f5c\u7528\u57df\u3002\u5168\u5c40\u4f5c\u7528\u57df\u5728\u9875\u9762\u6253\u5f00\u65f6\u521b\u5efa\uff0c\u5728\u9875\u9762\u5173\u95ed\u65f6\u9500\u6bc1\u3002\u5728\u5168\u5c40\u4f5c\u7528\u57df\u4e2d\u6709\u4e00\u4e2a\u5168\u5c40\u5bf9\u8c61window\uff0c\u6211\u4eec\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\uff0c\u5b83\u4ee3\u8868\u662f\u4e00\u4e2a\u6d4f\u89c8\u5668\u7684\u7a97\u53e3\uff0c\u5b83\u7531\u6d4f\u89c8\u5668\u521b\u5efa\u3002\u5728\u5168\u5c40\u4f5c\u7528\u57df\u4e2d\u521b\u5efa\u7684\u53d8\u91cf\u90fd\u4f1a\u4f5c\u4e3awindow\u5bf9\u8c61\u7684\u5c5e\u6027\u4fdd\u5b58\u3002\u521b\u5efa\u7684\u51fd\u6570\u90fd\u4f1a\u4f5c\u4e3awindow\u5bf9\u8c61\u7684\u65b9\u6cd5\u5b58\u5728\u3002
\u5168\u5c40\u4f5c\u7528\u57df\u4e2d\u7684\u53d8\u91cf\u90fd\u662f\u5168\u5c40\u53d8\u91cf\uff0c\u5728\u9875\u9762\u7684\u4efb\u610f\u4f4d\u7f6e\u90fd\u53ef\u4ee5\u8bbf\u95ee\u7684\u5230\u3002<\/p>\n\n\n\n

\u53d8\u91cf\u7684\u58f0\u660e\u63d0\u524d\uff1a
\u4f7f\u7528var\u5173\u952e\u5b57\u58f0\u660e\u7684\u53d8\u91cf\uff0c\u4f1a\u5728\u6240\u6709\u7684\u4ee3\u7801\u6267\u884c\u4e4b\u524d\u88ab\u58f0\u660e\uff08\u4f46\u4e0d\u4f1a\u8d4b\u503c\uff09\u3002\u4f46\u662f\u5982\u679c\u58f0\u660e\u53d8\u91cf\u65f6\u4e0d\u4f7f\u7528var\u5173\u952e\u5b57\uff0c\u5219\u53d8\u91cf\u4e0d\u4f1a\u88ab\u58f0\u660e\u63d0\u524d;<\/p>\n\n\n\n

\u51fd\u6570\u7684\u58f0\u660e\u63d0\u524d\uff1a
\u4f7f\u7528\u51fd\u6570\u58f0\u660e\u5f62\u5f0f\u521b\u5efa\u7684\u51fd\u6570\uff0c\u5728\u6240\u6709\u4ee3\u7801\u6267\u884c\u4e4b\u524d\u88ab\u521b\u5efa\uff0c\u6240\u4ee5\u53ef\u4ee5\u5728\u51fd\u6570\u58f0\u660e\u524d\u8c03\u7528\u3002\u4f7f\u7528\u51fd\u6570\u8868\u8fbe\u5f0f\u521b\u5efa\u7684\u51fd\u6570\uff0c\u4e0d\u4f1a\u88ab\u58f0\u660e\u63d0\u524d\uff0c\u6240\u4ee5\u4e0d\u80fd\u63d0\u524d\u4f7f\u7528\u3002<\/p>\n\n\n\n

\u51fd\u6570\u4f5c\u7528\u57df\uff1a
\u8c03\u7528\u51fd\u6570\u65f6\u521b\u5efa\u51fd\u6570\u4f5c\u7528\u57df\uff0c\u51fd\u6570\u6267\u884c\u5b8c\u6bd5\u4ee5\u540e\uff0c\u51fd\u6570\u4f5c\u7528\u57df\u9500\u6bc1\u3002\u6bcf\u8c03\u7528\u4e00\u6b21\u51fd\u6570\uff0c\u5c31\u4f1a\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u4f5c\u7528\u57df\uff0c\u4ed6\u4eec\u4e4b\u95f4\u662f\u4e92\u76f8\u72ec\u7acb\u7684\u3002\u5728\u51fd\u6570\u4f5c\u7528\u57df\u4e2d\uff0c\u53ef\u4ee5\u8bbf\u95ee\u5230\u5168\u5c40\u4f5c\u7528\u57df\u7684\u53d8\u91cf\u3002\u5168\u5c40\u4f5c\u7528\u57df\u4e2d\u65e0\u6cd5\u8bbf\u95ee\u5230\u5c40\u90e8\u4f5c\u7528\u57df\u7684\u53d8\u91cf\u3002\u5f53\u5728\u51fd\u6570\u4f5c\u7528\u57df\u4e2d\u64cd\u4f5c\u4e00\u4e2a\u53d8\u91cf\u65f6\uff0c\u5148\u5728\u81ea\u8eab\u4f5c\u7528\u57df\u4e2d\u5bfb\u627e\uff0c\u5982\u679c\u6709\u5c31\u76f4\u63a5\u4f7f\u7528\uff0c\u5982\u679c\u6ca1\u6709\u5c31\u5411\u4e0a\u7ea7\u4f5c\u7528\u57df\u4e2d\u5bfb\u627e\u3002
\u51fd\u6570\u4f5c\u7528\u57df\u4e2d\uff0c\u4e5f\u6709\u58f0\u660e\u63d0\u524d\u7684\u7279\u6027\u3002\u4f7f\u7528var\u5173\u952e\u5b57\u58f0\u660e\u7684\u53d8\u91cf\uff0c\u4f1a\u5728\u51fd\u6570\u4e2d\u6240\u6709\u7684\u4ee3\u7801\u6267\u884c\u4e4b\u524d\u88ab\u58f0\u660e\u3002\u51fd\u6570\u58f0\u660e\u4e5f\u4f1a\u5728\u51fd\u6570\u4e2d\u6240\u6709\u7684\u4ee3\u7801\u88ab\u6267\u884c\u524d\u58f0\u660e\u3002
\u5728\u51fd\u6570\u4e2d\uff0c\u4e0d\u4f7f\u7528var\u58f0\u660e\u7684\u53d8\u91cf\u90fd\u4f1a\u6210\u4e3a\u5168\u5c40\u53d8\u91cf\u3002
\u5b9a\u4e49\u5f62\u53c2\u5c31\u76f8\u5f53\u4e8e\u5728\u51fd\u6570\u4f5c\u7528\u57df\u4e2d\u58f0\u660e\u4e86\u4e00\u4e2a\u53d8\u91cf\u3002<\/p>\n\n\n\n

this:
\u89e3\u6790\u5668\u5728\u8c03\u7528\u51fd\u6570\u65f6\uff0c\u6bcf\u6b21\u90fd\u4f1a\u5411\u51fd\u6570\u5185\u90e8\u4f20\u9012\u8fdb\u4e00\u4e2a\u9690\u542b\u7684\u53c2\u6570\uff0c\u8fd9\u4e2a\u9690\u542b\u7684\u53c2\u6570\u5c31\u662fthis\u3002this\u6307\u5411\u7684\u662f\u4e00\u4e2a\u5bf9\u8c61\uff0c\u6211\u4eec\u79f0\u4e3a\u51fd\u6570\u6267\u884c\u7684\u4e0a\u4e0b\u6587\u5bf9\u8c61\u3002\u6839\u636e\u51fd\u6570\u8c03\u7528\u65b9\u5f0f\u4e0d\u540c\uff0cthis\u4f1a\u6307\u5411\u4e0d\u540c\u7684\u5bf9\u8c61\u3002
1.\u4ee5\u51fd\u6570\u5f62\u5f0f\u8c03\u7528\uff0cthis\u6c38\u8fdc\u90fd\u662fwindow;
2.\u4ee5\u65b9\u6cd5\u7684\u5f62\u5f0f\u8c03\u7528\uff0cthis\u5c31\u662f\u8c03\u7528\u65b9\u6cd5\u7684\u90a3\u4e2a\u5bf9\u8c61\u3002
3.\u5f53\u4ee5\u6784\u9020\u51fd\u6570\u7684\u65b9\u5f0f\u523b\u8c03\u7528\u65f6\uff0cthis\u5c31\u662f\u65b0\u521b\u5efa\u7684\u90a3\u4e2a\u5bf9\u8c61\u3002<\/p>\n\n\n\n

\u4f7f\u7528\u5de5\u5382\u65b9\u5f0f\u521b\u5efa\u5bf9\u8c61\uff1a<\/p>\n\n\n\n

\u6784\u9020\u51fd\u6570\uff1a
\u6784\u9020\u51fd\u6570\u5c31\u662f\u4e00\u4e2a\u666e\u901a\u7684\u51fd\u6570\uff0c\u521b\u5efa\u65b9\u5f0f\u548c\u666e\u901a\u51fd\u6570\u6ca1\u6709\u533a\u522b\u3002\u4e0d\u540c\u662f\u6784\u9020\u51fd\u6570\u4e60\u60ef\u4e0a\u9996\u5b57\u6bcd\u5927\u5199\u3002
\u6784\u9020\u51fd\u6570\u548c\u666e\u901a\u51fd\u6570\u7684\u533a\u522b\u5c31\u662f\u8c03\u7528\u65b9\u5f0f\u7684\u4e0d\u540c\u3002\u666e\u901a\u51fd\u6570\u76f4\u63a5\u8c03\u7528\uff0c\u800c\u6784\u9020\u51fd\u6570\u9700\u8981\u4f7f\u7528new\u5173\u952e\u5b57\u6765\u8c03\u7528\u3002
\u6267\u884c\u6d41\u7a0b\uff1a
1.\u7acb\u523b\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5bf9\u8c61;
2.\u5c06\u65b0\u5efa\u7684\u5bf9\u8c61\u8bbe\u7f6e\u4e3a\u51fd\u6570\u4e2d\u7684this\uff0c\u5728\u6784\u9020\u51fd\u6570\u4e2d\u53ef\u4ee5\u4f7f\u7528this\u6765\u5f15\u7528\u65b0\u5efa\u7684\u5bf9\u8c61\u3002
3.\u9010\u884c\u6267\u884c\u51fd\u6570\u4e2d\u7684\u4ee3\u7801\u3002
4.\u5c06\u65b0\u5efa\u7684\u5bf9\u8c61\u4f5c\u4e3a\u8fd4\u56de\u503c\u8fd4\u56de\u3002
\u4f7f\u7528\u540c\u4e00\u4e2a\u6784\u9020\u51fd\u6570\u521b\u5efa\u7684\u5bf9\u8c61\u79f0\u4e3a\u4e00\u7c7b\u5bf9\u8c61\uff0c\u4e5f\u5c06\u4e00\u4e2a\u6784\u9020\u51fd\u6570\u79f0\u4e3a\u4e00\u4e2a\u7c7b\u3002\u6211\u4eec\u5c06\u901a\u8fc7\u4e00\u4e2a\u6784\u9020\u51fd\u6570\u521b\u5efa\u7684\u5bf9\u8c61\u79f0\u4e3a\u7c7b\u7684\u5b9e\u4f8b\u3002<\/p>\n\n\n\n

instanceof\u8fd0\u7b97\u7b26\uff1a\u53ef\u4ee5\u68c0\u67e5\u4e00\u4e2a\u5bf9\u8c61\u662f\u5426\u662f\u4e00\u4e2a\u7c7b\u7684\u5b9e\u4f8b\u3002\u5982\uff1aconsole.log(per instanceof Person);
\u6240\u6709\u7684\u5bf9\u8c61\u90fd\u662fObject\u7684\u540e\u4ee3\u3002\u6240\u4ee5\u4efb\u4f55\u5bf9\u8c61\u548cObject\u505ainstanceof\u68c0\u67e5\u65f6\uff0c\u90fd\u4f1a\u8fd4\u56detrue\u3002<\/p>\n\n\n\n

\u539f\u578bprototype
\u6211\u4eec\u521b\u5efa\u7684\u6bcf\u4e00\u4e2a\u51fd\u6570\uff0c\u89e3\u6790\u5668\u90fd\u4f1a\u5411\u51fd\u6570\u4e2d\u6dfb\u52a0\u4e00\u4e2a\u5c5e\u6027prototype\uff0c\u8fd9\u4e2a\u5c5e\u6027\u5bf9\u5e94\u7740\u4e00\u4e2a\u5bf9\u8c61\uff0c\u8fd9\u4e2a\u5bf9\u8c61\u5c31\u662f\u6211\u4eec\u6240\u8c13\u7684\u539f\u578b\u5bf9\u8c61\u3002
\u5982\u679c\u51fd\u6570\u4f5c\u4e3a\u666e\u901a\u51fd\u6570\u8c03\u7528prototype\u6ca1\u6709\u4efb\u4f55\u4f5c\u7528\u3002
\u5f53\u51fd\u6570\u4ee5\u6784\u9020\u51fd\u6570\u5f62\u5f0f\u8c03\u7528\u65f6\uff0c\u5b83\u6240\u521b\u5efa\u7684\u5bf9\u8c61\u4e2d\u90fd\u4f1a\u6709\u4e00\u4e2a\u9690\u542b\u7684\u5c5e\u6027\uff0c\u6307\u5411\u8be5\u6784\u9020\u51fd\u6570\u7684\u539f\u578b\u5bf9\u8c61\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7__proto__\u5c5e\u6027\u6765\u8bbf\u95ee\u8be5\u5c5e\u6027\u3002
\u539f\u578b\u5bf9\u8c61\u76f8\u5f53\u4e8e\u4e00\u4e2a\u516c\u5171\u7684\u533a\u57df\uff0c\u6240\u6709\u540c\u4e00\u4e2a\u7c7b\u7684\u5b9e\u4f8b\u90fd\u53ef\u4ee5\u8bbf\u95ee\u5230\u8fd9\u4e2a\u539f\u578b\u5bf9\u8c61\u3002\u6211\u4eec\u53ef\u4ee5\u5c06\u5bf9\u8c61\u4e2d\u5171\u6709\u7684\u5185\u5bb9\uff0c\u7edf\u4e00\u8bbe\u7f6e\u5230\u539f\u578b\u5bf9\u8c61\u4e2d\u3002
\u5f53\u6211\u4eec\u8bbf\u95ee\u5bf9\u8c61\u7684\u4e00\u4e2a\u5c5e\u6027\u6216\u65b9\u6cd5\u65f6\uff0c\u5b83\u4f1a\u5148\u5728\u5bf9\u8c61\u81ea\u8eab\u4e2d\u5bfb\u627e\uff0c\u5982\u679c\u6709\uff0c\u5219\u76f4\u63a5\u4f7f\u7528; \u5982\u679c\u6ca1\u6709\uff0c\u5219\u4f1a\u53bb\u539f\u578b\u5bf9\u8c61\u4e2d\u5bfb\u627e\u3002
\u4ee5\u540e\u6211\u4eec\u521b\u5efa\u6784\u9020\u51fd\u6570\u65f6\uff0c\u53ef\u4ee5\u5c06\u8fd9\u4e9b\u5bf9\u8c61\u5171\u6709\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u7edf\u4e00\u6dfb\u52a0\u5230\u6784\u9020\u51fd\u6570\u7684\u539f\u578b\u5bf9\u8c61\u4e2d\uff0c\u8fd9\u6837\u4e0d\u7528\u5206\u522b\u4e3a\u6bcf\u4e00\u4e2a\u5bf9\u8c61\u6dfb\u52a0\uff0c\u4e5f\u4e0d\u4f1a\u5f71\u54cd\u5230\u5168\u5c40\u4f5c\u7528\u57df\uff0c\u5c31\u53ef\u4ee5\u4f7f\u6bcf\u4e2a\u5bf9\u8c61\u90fd\u5177\u6709\u8fd9\u4e9b\u5c5e\u6027\u548c\u65b9\u6cd5\u4e86\u3002<\/p>\n\n\n\n

\u4f7f\u7528in\u68c0\u67e5\u5bf9\u8c61\u4e2d\u662f\u5426\u6709\u67d0\u4e2a\u5c5e\u6027\u65f6\uff0c\u5982\u679c\u5bf9\u8c61\u4e2d\u6ca1\u6709\u4f46\u662f\u539f\u578b\u4e2d\u6709\uff0c\u4e5f\u4f1a\u8fd4\u56detrue\u3002\u53ef\u4ee5\u4f7f\u7528hasOwnProperty()\u6765\u68c0\u67e5\u81ea\u8eab\u4e2d\u662f\u5426\u542b\u6709\u8be5\u5c5e\u6027\u3002<\/p>\n\n\n\n

\u539f\u578b\u5bf9\u8c61\u4e5f\u662f\u5bf9\u8c61\uff0c\u6240\u4ee5\u5b83\u4e5f\u6709\u539f\u578b\u3002\u5f53\u6211\u4eec\u4f7f\u7528\u4e00\u4e2a\u5bf9\u8c61\u7684\u5c5e\u6027\u6216\u65b9\u6cd5\u65f6\uff0c\u4f1a\u5148\u5728\u81ea\u8eab\u4e2d\u5bfb\u627e\uff0c\u81ea\u8eab\u4e2d\u5982\u679c\u6709\uff0c\u5219\u76f4\u63a5\u4f7f\u7528\uff0c\u5982\u679c\u6ca1\u6709\u5219\u53bb\u539f\u578b\u5bf9\u8c61\u4e2d\u5bfb\u627e\uff0c\u76f4\u5230\u627e\u5230Object\u5bf9\u8c61\u7684\u539f\u578b\u3002Object\u5bf9\u8c61\u7684\u539f\u578b\u6ca1\u6709\u539f\u578b\uff0c\u5982\u679c\u5728Object\u4e2d\u4f9d\u7136\u6ca1\u6709\u627e\u5230\uff0c\u5219\u8fd4\u56deundefined\u3002<\/p>\n\n\n\n

toString():\u5f53\u6211\u4eec\u76f4\u63a5\u5728\u9875\u9762\u4e2d\u6253\u5370\u4e00\u4e2a\u5bf9\u8c61\u65f6\uff0c\u5b9e\u9645\u4e0a\u662f\u8f93\u51fa\u7684\u5bf9\u8c61\u7684toString()\u65b9\u6cd5\u7684\u8fd4\u56de\u503c\u3002\u5982\u679c\u6211\u4eec\u5e0c\u671b\u5728\u8f93\u51fa\u5bf9\u8c61\u65f6\u4e0d\u8f93\u51fa[object Object]\uff0c\u53ef\u4ee5\u4e3a\u5bf9\u8c61\u6dfb\u52a0\u4e00\u4e2atoString()\u65b9\u6cd5\u3002<\/p>\n\n\n\n

\u5783\u573e\u56de\u6536\uff08GC\uff09\uff1a
\u5c31\u50cf\u4eba\u751f\u6d3b\u65f6\u95f4\u957f\u4e86\u4f1a\u4ea7\u751f\u5783\u573e\u4e00\u6837\uff0c\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\u4e5f\u4f1a\u4ea7\u751f\u5783\u573e\uff0c\u8fd9\u4e9b\u5783\u573e\u79ef\u6512\u8fc7\u591a\u4ee5\u540e\uff0c\u4f1a\u5bfc\u81f4\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u6162\uff0c\u6240\u4ee5\u9700\u8981\u4e00\u4e2a\u5783\u573e\u56de\u6536\u673a\u5236\uff0c\u6765\u5904\u7406\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\u7684\u5783\u573e\u3002\u5f53\u4e00\u4e2a\u5bf9\u8c61\u6ca1\u6709\u4efb\u4f55\u7684\u53d8\u91cf\u6216\u5c5e\u6027\u5bf9\u5b83\u8fdb\u884c\u5f15\u7528\uff0c\u6b64\u65f6\u6211\u4eec\u5c06\u6c38\u8fdc\u6ca1\u6cd5\u7ee7\u7eed\u4f7f\u7528\uff0c\u6b64\u65f6\u8fd9\u79cd\u5bf9\u8c61\u5c31\u50cf\u5783\u573e\uff0c\u4f1a\u5360\u7528\u5927\u91cf\u7684\u5185\u5b58\u7a7a\u95f4\uff0c\u5bfc\u81f4\u7a0b\u5e8f\u8fd0\u884c\u53d8\u6162\u3002\u5728JS\u4e2d\u62e5\u6709\u81ea\u52a8\u7684\u5783\u573e\u56de\u6536\u673a\u5236\uff0c\u4f1a\u81ea\u52a8\u5c06\u8fd9\u4e9b\u5783\u573e\u5bf9\u8c61\u4ece\u5185\u5b58\u4e2d\u9500\u6bc1\uff0c\u6211\u4eec\u4e0d\u9700\u8981\u4e5f\u4e0d\u80fd\u8fdb\u884c\u5783\u573e\u56de\u6536\u7684\u64cd\u4f5c\u3002\u4f46\u662f\u5fc5\u987b\u5c06\u5bf9\u8c61\u7684\u5f15\u7528\u65ad\u5f00\uff0c\u5982obj=null\u3002<\/p>\n\n\n\n

\u6570\u7ec4<\/h2>\n\n\n\n

\u5bf9\u8c61\u5206\u4e09\u7c7b\uff1a\u5185\u5efa\u5bf9\u8c61\u3001\u5bbf\u4e3b\u5bf9\u8c61\u3001\u81ea\u5b9a\u4e49\u5bf9\u8c61<\/p>\n\n\n\n

\u6570\u7ec4\uff08Array\uff09\u4e5f\u662f\u4e00\u4e2a\u5bf9\u8c61\uff0c\u5b83\u548c\u6211\u4eec\u666e\u901a\u7684\u5bf9\u8c61\u529f\u80fd\u7c7b\u4f3c\uff0c\u4e5f\u662f\u7528\u6765\u5b58\u50a8\u4e00\u4e9b\u503c\u7684\u3002
\u4e0d\u540c\u7684\u662f\u666e\u901a\u5bf9\u8c61\u662f\u4f7f\u7528\u5b57\u7b26\u4e32\u4f5c\u4e3a\u5c5e\u6027\u540d\u7684\uff0c\u800c\u6570\u7ec4\u662f\u4f7f\u7528\u6570\u5b57\u4f5c\u4e3a\u7d22\u5f15\u6765\u64cd\u4f5c\u5143\u7d20\u3002
\u7d22\u5f15\uff1a\u4ece0\u5f00\u59cb\u7684\u6574\u6570\u5e8f\u5217\u3002
\u6570\u7ec4\u7684\u5b58\u50a8\u6027\u80fd\u6bd4\u666e\u901a\u5bf9\u8c61\u8981\u597d\uff0c\u5728\u5f00\u53d1\u4e2d\u6211\u4eec\u7ecf\u5e38\u4f7f\u7528\u6570\u7ec4\u6765\u5b58\u50a8\u4e00\u4e9b\u6570\u636e\u3002<\/p>\n\n\n\n

\u521b\u5efa\u6570\u7ec4\u5bf9\u8c61\uff1a<\/h3>\n\n\n\n
var arr = new Array();\n\/\/\u4f7f\u7528typeof\u68c0\u67e5\u4e00\u4e2a\u6570\u7ec4\u65f6\uff0c\u4f1a\u8fd4\u56de\u201cobject\u201d\n\/\/\u5411\u6570\u7ec4\u4e2d\u6dfb\u52a0\u5143\u7d20\uff0c\u8bed\u6cd5\uff1a\u6570\u7ec4[\u7d22\u5f15]=\u503c\narr[0]=10;\narr[1]=33;\n\/\/\u8bfb\u53d6\u5143\u7d20.\u5982\u679c\u8bfb\u53d6\u4e0d\u5b58\u5728\u7684\u7d22\u5f15\uff0c\u4e0d\u62a5\u9519\uff0c\u8fd4\u56de\u201cundefined\u201d\narr[0]<\/code><\/pre>\n\n\n\n
\u4f7f\u7528length\u5c5e\u6027\u6765\u83b7\u53d6\u6570\u7ec4\u7684\u957f\u5ea6<\/h3>\n\n\n\n
\u8bed\u6cd5\uff1a arr.length;
\u5bf9\u4e8e\u8fde\u7eed\u7684\u6570\u7ec4\uff0c\u4f7f\u7528length\u53ef\u4ee5\u83b7\u53d6\u6570\u7ec4\u5143\u7d20\u7684\u4e2a\u6570\u3002\u5bf9\u4e8e\u975e\u8fde\u7eed\u7684\u6570\u7ec4\uff0c\u4f7f\u7528length\u4f1a\u83b7\u53d6\u5230\u6570\u7ec4\u6700\u5927\u7684\u7d22\u5f15\u52a01\u3002
\u5982\u679c\u4fee\u6539\u7684length\u5927\u4e8e\u539f\u957f\u5ea6\uff0c\u5219\u591a\u51fa\u90e8\u5206\u4f1a\u7a7a\u51fa\u6765\u3002\u5c0f\u4e8e\u539f\u957f\u5ea6\u7684\u8bdd\uff0c\u5219\u622a\u53d6\u524d\u9762\u7684\u90e8\u5206\uff0c\u591a\u51fa\u7684\u5143\u7d20\u88ab\u5220\u9664\u3002<\/p>\n\n\n\n
\u6570\u7ec4\u904d\u5386\u65b9\u6cd5
1\uff1afor(var i=0;i<arr.length;i++){}
2.forEach()\u65b9\u6cd5\uff1a\u6b64\u65b9\u6cd5\u9700\u8981\u4e00\u4e2a\u51fd\u6570\u4f5c\u4e3a\u53c2\u6570\uff0c\u50cf\u8fd9\u79cd\u51fd\u6570\uff0c\u7531\u6211\u4eec\u521b\u5efa\u4f46\u662f\u4e0d\u7531\u6211\u4eec\u8c03\u7528\uff0c\u79f0\u4e3a\u56de\u8c03\u51fd\u6570\u3002\u6570\u7ec4\u4e2d\u6709\u51e0\u4e2a\u5143\u7d20\uff0c\u5219\u6b64\u51fd\u6570\u5c31\u4f1a\u6267\u884c\u51e0\u6b21\u3002\u6bcf\u6b21\u6267\u884c\u65f6\uff0c\u6d4f\u89c8\u5668\u5c31\u4f1a\u5c06\u904d\u5386\u5230\u7684\u5143\u7d20\u4ee5\u5b9e\u53c2\u7684\u5f62\u5f0f\u4f20\u9012\u8fdb\u6765\uff0c\u6211\u4eec\u53ef\u4ee5\u5b9a\u4e49\u5f62\u53c2\uff0c\u6765\u8bfb\u53d6\u8fd9\u4e9b\u5185\u5bb9\u3002\u7b2c\u4e00\u4e2a\u53c2\u6570\uff0c\u5f53\u524d\u6b63\u5728\u904d\u5386\u7684\u5143\u7d20\u503c\uff0c\u7b2c\u4e8c\u4e2a\u53c2\u6570\u4e3a\u5f53\u524d\u904d\u5386\u7684\u5143\u7d20\u7684\u7d22\u5f15; \u7b2c\u4e09\u4e2a\u53c2\u6570\u4e3a\u5f53\u524d\u6570\u7ec4\u3002<\/p>\n\n\n\n
\u5b57\u7b26\u4e32\uff1a<\/p>\n\n\n\n
\u5728\u5e95\u5c42\u5b57\u7b26\u4e32\u662f\u4ee5\u5b57\u7b26\u6570\u7ec4\u7684\u5f62\u5f0f\u4fdd\u5b58\u7684\u3002str.length\u3002str[0]\u3002
length\uff1a\u5c5e\u6027\uff0c\u53ef\u4ee5\u7528\u6765\u83b7\u53d6\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u3002
charAt(): \u8fd4\u56de\u5b57\u7b26\u4e32\u4e2d\u6307\u5b9a\u4f4d\u7f6e\u7684\u5b57\u7b26\u3002\u6839\u636e\u7d22\u5f15\u83b7\u53d6\u6307\u5b9a\u7684\u5b57\u7b26\u3002
charCodeAt(): \u83b7\u53d6\u6307\u5b9a\u4f4d\u7f6e\u5b57\u7b26\u7684Unicode\u7f16\u7801\u3002
String.fromCharCode(): \u53ef\u4ee5\u6839\u636e\u5b57\u7b26\u7f16\u7801\u53bb\u83b7\u53d6\u5b57\u7b26\u3002\u5982String.fromCharCode(20035),\u5f97\u5230\u201c\u4e43\u201d\u3002
concat(): \u8fde\u63a5\u5b57\u7b26\u4e32\u3002
indexOf(): \u68c0\u7d22\u4e00\u4e2a\u5b57\u7b26\u4e32\u4e2d\u662f\u5426\u542b\u6709\u6307\u5b9a\u5185\u5bb9\u3002\u8fd4\u56de\u5b57\u7b26\u4e32\u6240\u5728\u4f4d\u7f6e\u7d22\u5f15\u3002
lastIndexOf():\u4ece\u540e\u5411\u524d\u641c\u7d22\u5b57\u7b26\u3002
slice(): \u4ece\u5b57\u7b26\u4e32\u4e2d\u622a\u53d6\u5b57\u7b26\u3002
substring(): \u8ddfslice\u57fa\u672c\u4e00\u6837\u3002\u4e0d\u540c\u7684\u662f\u8fd9\u4e2a\u65b9\u6cd5\u4e0d\u80fd\u63a5\u53d7\u8d1f\u503c\uff0c\u5982\u679c\u4f7f\u7528\u8d1f\u503c\uff0c\u5219\u9ed8\u8ba4\u4f7f\u75280\uff0c\u800c\u4e14\u4ed6\u8fd8\u4f1a\u81ea\u52a8\u8c03\u6574\u53c2\u6570\u7684\u4f4d\u7f6e\uff0c\u5982\u679c\u7b2c\u4e8c\u4e2a\u53c2\u6570\u5c0f\u4e8e\u7b2c\u4e00\u4e2a\uff0c\u5219\u81ea\u52a8\u4ea4\u6362\u53c2\u6570\u4f4d\u7f6e\u3002
substr():
split(): \u5c06\u5b57\u7b26\u4e32\u62c6\u5206\u4e3a\u4e00\u4e2a\u6570\u7ec4\u3002<\/p>\n\n\n\n
ES6\uff1a<\/h2>\n\n\n\n
let\uff1a
1.\u53d8\u91cf\u4e0d\u80fd\u91cd\u590d\u58f0\u660e\u3002var\u53ef\u4ee5\u3002
2.\u5757\u7ea7\u4f5c\u7528\u57df\u3002ES5\u4e2d\u6709\u4e09\u79cd\u4f5c\u7528\u57df\uff1a\u5168\u5c40\u3001\u51fd\u6570\u3001eval\u3002
3.\u4e0d\u5b58\u5728\u53d8\u91cf\u63d0\u5347\u3002
4.\u4e0d\u5f71\u54cd\u4f5c\u7528\u57df\u94fe\u3002<\/p>\n\n\n\n
const\u5b9a\u4e49\u5e38\u91cf:
1.\u4e00\u5b9a\u8981\u8d4b\u521d\u503c\u3002
2.\u4e00\u822c\u5e38\u91cf\u540d\u4f7f\u7528\u5927\u5199\uff08\u6f5c\u89c4\u5219\uff09
3.\u5e38\u91cf\u503c\u4e0d\u80fd\u4fee\u6539\u3002
4.\u5757\u7ea7\u4f5c\u7528\u57df\u3002
5.\u5bf9\u4e8e\u6570\u7ec4\u548c\u5bf9\u8c61\u7684\u5143\u7d20\u4fee\u6539\uff0c\u4e0d\u7b97\u505a\u5bf9\u5e38\u91cf\u7684\u4fee\u6539\uff0c\u4e0d\u4f1a\u62a5\u9519\u3002<\/p>\n\n\n\n
\u53d8\u91cf\u7684\u89e3\u6784\u8d4b\u503c\uff1a<\/h3>\n\n\n\n
 1.\u6570\u7ec4\u7684\u89e3\u6784\n   const F4=['\u5c0f\u6c88\u9633','\u5218\u80fd','\u8d75\u56db','\u5b8b\u5c0f\u5b9d']\n   let [xiao,liu,zhao,song] = F4;\n   console.log(xiao);\n   console.log(liu);\n   console.log(zhao);\n   console.log(song);\n\n2.\u5bf9\u8c61\u7684\u89e3\u6784\uff1a\n    const zhao={\n        name:'\u8d75\u672c\u5c71',\n        age:'\u4e0d\u8be6',\n        xiaopin:function(){\n            console.log(\"\u6211\u53ef\u4ee5\u6f14\u5c0f\u54c1\")\n        }\n     }\n\n      let {name,age,xiaopin}=zhao\n      let {xiaopin}=zhao;<\/code><\/pre>\n\n\n\n
\u6a21\u677f\u5b57\u7b26\u4e32\uff1a<\/h2>\n\n\n\n
ES6\u4e2d\u5f15\u5165\u65b0\u7684\u58f0\u660e\u5b57\u7b26\u4e32\u7684\u65b9\u5f0f  “
\u5185\u5bb9\u4e2d\u53ef\u4ee5\u76f4\u63a5\u51fa\u73b0\u6362\u884c\u7b26\u3002
\u53ef\u4ee5\u76f4\u63a5\u8fdb\u884c\u53d8\u91cf\u7684\u62fc\u63a5\u3002`${\u53d8\u91cf\u540d}\u662f\u6211\u5fc3\u76ee\u4e2d\u6700\u641e\u7b11\u7684\u6f14\u5458`\u3002<\/p>\n\n\n\n
\u5bf9\u8c61\u7684\u7b80\u5316\u5199\u6cd5\uff1a<\/h2>\n\n\n\n
ES6\u5141\u8bb8\u5728\u5927\u62ec\u53f7\u91cc\u9762\uff0c\u76f4\u63a5\u5199\u5165\u53d8\u91cf\u548c\u51fd\u6570\uff0c\u4f5c\u4e3a\u5bf9\u8c61\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u8fd9\u6837\u7684\u4e66\u5199\u66f4\u52a0\u7b80\u6d01\u3002
\u65b9\u6cd5\u58f0\u660e\u7684\u7b80\u5316\uff1a<\/p>\n\n\n\n
     let name='\u5c1a\u7845\u8c37'\n     let change=function(){\n         console.log('\u6211\u4eec\u53ef\u4ee5\u6539\u53d8\u4f60')\n     }\n     const school={\n         name:name,\n         change:change,\n         improve:function(){\n             console.log(\"\u6211\u4eec\u53ef\u4ee5\u63d0\u9ad8\u4f60\u7684\u6280\u80fd\")\n         }\n     }\n     \u7b80\u5199\u4e3a\uff1a\n     const school={\n         name,\n         change,\n         improve(){\n             console.log(\"\u6211\u4eec\u53ef\u4ee5\u63d0\u9ad8\u4f60\u7684\u6280\u80fd\")\n         }\n     }<\/code><\/pre>\n\n\n\n
\u7b80\u5934\u51fd\u6570\uff1a<\/h3>\n\n\n\n
1.this\u662f\u9759\u6001\u7684\uff0c\u59cb\u7ec8\u6307\u5411\u51fd\u6570\u58f0\u660e\u65f6\u6240\u5728\u4f5c\u7528\u57df\u4e0b\u7684this\u503c\u3002
2.\u4e0d\u80fd\u4f5c\u4e3a\u6784\u9020\u51fd\u6570\u5b9e\u4f8b\u5316\u5bf9\u8c61\u3002
3.\u4e0d\u80fd\u4f7f\u7528arguments\u53d8\u91cf\u3002
4.\u7bad\u5934\u51fd\u6570\u7b80\u5199\uff1a\u7701\u7565\u5c0f\u62ec\u53f7\uff0c\u5f53\u5f62\u53c2\u6709\u4e14\u53ea\u6709\u4e00\u4e2a\u7684\u65f6\u5019\uff1b\u5f53\u4ee3\u7801\u4f53\u53ea\u6709\u4e00\u6761\u8bed\u53e5\u7684\u65f6\u5019\uff0c\u53ef\u4ee5\u7701\u7565\u82b1\u62ec\u53f7\uff0c\u6b64\u65f6return \u5fc5\u987b\u7701\u7565\uff0c\u800c\u4e14\u8bed\u53e5\u7684\u6267\u884c\u7ed3\u679c\u5c31\u662f\u51fd\u6570\u7684\u8fd4\u56de\u503c\u3002
\u7bad\u5934\u51fd\u6570\u9002\u5408\u4e0ethis\u65e0\u5173\u7684\u56de\u8c03\uff0c\u5b9a\u65f6\u5668\uff0c\u6570\u7ec4\u7684\u65b9\u6cd5\u56de\u8c03\u3002
\u4e0d\u9002\u5408\u4e0ethis\u6709\u5173\u7684\u573a\u666f\uff0c\u5982DOM\u5143\u7d20\u4e8b\u4ef6\u56de\u8c03\u3001\u5bf9\u8c61\u7684\u65b9\u6cd5\u3002<\/p>\n\n\n\n
\u7ed9\u51fd\u6570\u53c2\u6570\u8d4b\u521d\u59cb\u503c\uff1a<\/h3>\n\n\n\n
\u5177\u6709\u9ed8\u8ba4\u503c\u7684\u53c2\u6570\uff0c\u4e00\u822c\u4f4d\u7f6e\u8981\u9760\u540e\uff08\u6f5c\u89c4\u5219\uff09\u3002
\u9ed8\u8ba4\u503c\u53ef\u4ee5\u4e0e\u89e3\u6784\u8d4b\u503c\u7ed3\u5408\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
rest\u53c2\u6570<\/h3>\n\n\n\n
ES6\u5f15\u5165rest\u53c2\u6570\uff0c\u7528\u4e8e\u83b7\u53d6\u51fd\u6570\u7684\u5b9e\u53c2\uff0c\u7528\u6765\u4ee3\u66ffarguments.arguments \u662f\u4e00\u4e2a\u5bf9\u8c61\u3002\u800crest\u662f\u4e00\u4e0b\u7eaf\u6570\u7ec4\u3002
rest\u53c2\u6570\u5fc5\u987b\u653e\u5230\u53c2\u6570\u6700\u540e\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\u6269\u5c55\u8fd0\u7b97\u7b26\uff1a<\/h3>\n\n\n\n
“…”\u6269\u5c55\u8fd0\u7b97\u7b26\u80fd\u5c06\u6570\u7ec4\u8f6c\u6362\u4e3a\u9017\u53f7\u5206\u9694\u7684\u53c2\u6570\u5e8f\u5217\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\u5e94\u75281\uff1a\u6570\u7ec4\u7684\u5408\u5e76<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\u5e94\u75282\uff1a\u6570\u7ec4\u7684\u514b\u9686<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\u5e94\u75283\uff1a\u5c06\u4f2a\u6570\u7ec4\u8f6c\u4e3a\u771f\u6b63\u7684\u6570\u7ec4<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
Symbol:<\/h3>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\u7ed9\u5bf9\u8c61\u6dfb\u52a0\u5c5e\u6027\u548c\u65b9\u6cd5\uff1a<\/p>\n\n\n\n
Set\u96c6\u5408\u4ecb\u7ecd\u4e0eAPI<\/h3>\n\n\n\n
\/\/\u58f0\u660e\u4e00\u4e2aset\nlet s = new Set();\n\/\/\u4f20\u5165\u4e00\u4e2a\u53ef\u8fed\u4ee3\u5bf9\u8c61\uff0c\u4e00\u822c\u4e3a\u4e00\u6570\u7ec4\u3002\u4f1a\u81ea\u52a8\u53bb\u91cd\nlet s2 = new Set(['\u5927\u4e8b\u513f','\u5c0f\u4e8b\u513f','\u597d\u4e8b\u513f','\u574f\u5e26\u513f','\u5c0f\u4e8b\u513f']);  \n\/\/\u5143\u7d20\u4e2a\u6570\nconsole.log(s2.size);  \/\/4\n\/\/\u6dfb\u52a0\u65b0\u7684\u5143\u7d20\ns2.add('\u559c\u4e8b\u513f');\n\/\/\u5220\u9664\u5143\u7d20\ns2.delete('\u574f\u4e8b\u513f');\n\/\/\u68c0\u6d4b\ns2.has('\u597d\u4e8b\u513f');\n\/\/\u6e05\u7a7a\ns2.clear();\n\/\/\u96c6\u5408\u5b9e\u73b0\u4e86iterator\u63a5\u53e3\uff0c\u5e2e\u53ef\u4ee5\u4f7f\u7528for ...of...\n\/\/set\u96c6\u5408\u5b9e\u8df5\nlet arr=[1,2,3,4,6,4,3,2,1];\n1.\u6570\u7ec4\u53bb\u91cd\nlet result=[...new Set(arr)];\n2.\u4ea4\u96c6\nlet arr2=[4,5,6,5,6];\nlet result=[...new Set(arr)].filter(item=>new Set(arr2).has(item));\n3.\u5e76\u96c6\nlet union=[...new Set([...arr,...arr2])];\n4.\u5dee\u96c6\nlet diff = [...new Set(arr)].filter(item=>!(new Set(arr2).has(item)));<\/code><\/pre>\n\n\n\n
Map\u7684\u4ecb\u7ecd\u4e0eAPI<\/h3>\n\n\n\n
\u5347\u7ea7\u7248\u7684\u5bf9\u8c61\u3002<\/p>\n\n\n\n
\/\/\u58f0\u660e\nlet m = new Map();\n\/\/\u6dfb\u52a0\u5143\u7d20\nm.set('name','\u5c1a\u7845\u8c37');\nm.set('change',function(){console.log(\"\u6211\u4eec\u53ef\u4ee5\u6539\u53d8\u4f60\")});\n\nlet key={\n    school:'ATGUIGU'\n};\nm.set(key,['\u5317\u4eac','\u4e0a\u6d77','\u6df1\u5733'];\n\n\/\/size console.log(m.size);\n\/\/\u5220\u9664\nm.delete('name');\n\/\/\u83b7\u53d6\nm.get('change');\nm.get(key);\n\/\/\u6e05\u7a7a\nm.clear();\n\/\/\u904d\u5386\nfor(let v of m){\n    \n}<\/code><\/pre>\n\n\n\n
Class\u4ecb\u7ecd\u4e0e\u521d\u4f53\u9a8c<\/h3>\n\n\n\n
ES6\u7684\u5bf9\u8c61\u65b9\u6cd5\u6269\u5c55<\/h3>\n\n\n\n
1.Object.is\u5224\u65ad\u4e24\u4e2a\u503c\u662f\u5426\u5b8c\u5168\u76f8\u7b49\u3002\u4f5c\u7528\u8ddf===\u5f88\u50cf\u3002\u5224\u65ad\u4e24\u4e2aNaN\uff0c\u7ed3\u679c\u662ftrue\u3002
2.Object.assign\u5bf9\u8c61\u7684\u5408\u5e76\u3002
3.Object.setPrototypeOf\u8bbe\u7f6e\u539f\u578b\u5bf9\u8c61  Object.getPrototypeof<\/p>\n\n\n\n
\u6a21\u5757\u5316<\/h3>\n\n\n\n
\u6a21\u5757\u5316\u662f\u5c06\u4e00\u4e2a\u5927\u7684\u7a0b\u5e8f\u6587\u4ef6\uff0c\u62c6\u5206\u6210\u8bb8\u591a\u5c0f\u7684\u6587\u4ef6\uff0c\u7136\u540e\u5c06\u5c0f\u6587\u4ef6\u7ec4\u5408\u8d77\u6765\u3002
\u597d\u5904\uff1a1\u9632\u6b62\u547d\u540d\u51b2\u7a81; 2\u4ee3\u7801\u590d\u7528\uff1b3\u9ad8\u7ef4\u62a4\u6027\u3002
\u6a21\u5757\u5316\u89c4\u8303\u4ea7\u54c1\uff1a CommonJS\uff08NodeJS\u3001Browserify\uff09;  AMD\uff08requireJS\uff09\uff1bCMD(seaJS)
ES6\u6a21\u5757\u5316\u8bed\u6cd5\uff1a
    \u4e3b\u8981\u7531\u4e24\u4e2a\u547d\u4ee4\u6784\u6210\uff1aexport\u548cimport\u3002
    \u66b4\u9732\u8bed\u6cd5\u6709\u4e09\u79cd\uff1a<\/p>\n\n\n\n
\/\/\u5206\u522b\u66b4\u9732\nexport let school='\u5c1a\u7845\u8c37'\n\nexport function teach()\n{\n    console.log(\"\u6211\u4eec\u53ef\u4ee5\u6559\u7ed9\u4f60\u5f00\u53d1\u6280\u80fd\")\n}\n\nlet school = '\u5c1a\u7845\u8c37'\n\nfunction findJob()\n{\n    console.log(\"\u6211\u4eec\u53ef\u4ee5\u5e2e\u52a9\u4f60\u627e\u5de5\u4f5c\uff01\")\n}\n\n\/\/\u7edf\u4e00\u66b4\u9732\nexport {school,findJob}\n\n\/\/\u9ed8\u8ba4\u66b4\u9732\nexport default {\n    school:'ATGUIGU',\n    change: function()\n    {\n        console.log(\"\u6211\u4eec\u53ef\u4ee5\u6539\u53d8\u4f60\")\n    }\n}<\/code><\/pre>\n\n\n\n
    \u5f15\u5165\u8bed\u6cd5\u6c47\u603b\uff1a<\/p>\n\n\n\n
    <script type=\"module\">\n        \/\/\u5f15\u5165m1.js\u6a21\u5757\u5185\u5bb9\n        import * as m1 from \".\/m1.js\"\n        import * as m2 from \".\/m1.js\"\n        \n        \/\/\u89e3\u6784\u8d4b\u503c\u5f62\u5f0f\n        import {school,teach} from \".\/m1.js\"\n        import {school as guigu,teach} from \".\/m2.js\" \/\/\u4f7f\u7528\u522b\u540d\n\n        import {default as m3} from \".\/m3.js\"\n\n        \/\/\u7b80\u4fbf\u5f62\u5f0f\uff0c\u53ea\u9488\u5bf9\u9ed8\u8ba4\u66b4\u9732\n        import m3 from \".\/m3.js\"\n    <\/script><\/code><\/pre>\n\n\n\n
\u6d4f\u89c8\u5668\u4f7f\u7528ES6\u6a21\u5757\u5316\u65b9\u5f0f\u4e8c\uff1a
    \u521b\u5efaapp.js\uff0c\u4f5c\u4e3a\u5165\u53e3\uff0c\u5f15\u5165\u6a21\u5757; \u5728\u524d\u7aefhtml\u6587\u4ef6\u4e2d\u53ea\u5f15\u5165app.js\uff0ctype\u8ba4\u4e3amodule\u3002<\/p>\n\n\n\n
ES6\u6a21\u5757\u5316\u4ee3\u7801\u5728\u9879\u76ee\u4e2d\u7684\u4f7f\u7528\uff1a
    1.\u5b89\u88c5\u5de5\u5177\uff1abalel-cli bable_preset-env browserify(\u6253\u5305\u5de5\u5177\u3001\u76f8\u5bf9\u7b80\u5355\uff09<\/p>\n\n\n\n
\/\/\u521d\u59cb\u5316\nnpm init --yes\n\/\/-D\u4ee3\u8868\u5f00\u53d1\u4f9d\u8d56\nnpm i babel-cli babel-preset-env browserify -D\n\/\/\u5c40\u90e8\u5b89\u88c5\uff0c\u6240\u4ee5\u7528npx\nnpx babel src\/js -d dist\/js --preset=babel-preset-env\n\/\/\u6253\u5305 \nnpx browserify dist\/js\/app.js -o dist\/bundle.js\n\/\/\u6700\u7ec8\u5728html\u6587\u4ef6\u4e2d\u5f15\u5165bundle.js\u5373\u53ef\n<script src=\"dist\/js\/bundle.js\"><\/script><\/code><\/pre>\n\n\n\n
ES6\u6a21\u5757\u5f15\u5165NPM\u5305<\/p>\n\n\n\n
\/\/\u7b2c\u4e00\u6b65\uff0c\u4f7f\u7528npm\u5b89\u88c5jquery\nnpm i jquery\n\/\/\u5230\u5165\u53e3\u6587\u4ef6app.js\u5f15\u5165\u6a21\u5757\nimport $ from 'jquery'; \n$('body').css('background','pink');\n\/\/\u91cd\u65b0\u8f6c\u5316\u3001\u6253\u5305\n\/\/\u5c40\u90e8\u5b89\u88c5\uff0c\u6240\u4ee5\u7528npx\nnpx babel src\/js -d dist\/js --preset=babel-preset-env\n\/\/\u6253\u5305 \nnpx browserify dist\/js\/app.js -o dist\/bundle.js<\/code><\/pre>\n\n\n\n
Promise:<\/h2>\n\n\n\n
Nodejs<\/h2>\n\n\n\n

clientHeight\u3001clientWidth: \u53ef\u89c1\u7684\u9ad8\u5ea6\u3001\u5bbd\u5ea6\uff0c\u8fd9\u4e9b\u5c5e\u6027\u90fd\u662f\u4e0d\u5e26px\u7684\uff0c\u8fd4\u56de\u4e00\u4e2a\u6570\u5b57\uff0c\u53ef\u4ee5\u76f4\u63a5\u8ba1\u7b97\uff0c\u5305\u542b\u5185\u5bb9\u533a\u548c\u5185\u8fb9\u8ddd\u3002\u5c5e\u6027\u662f\u53ea\u8bfb\u7684\uff0c\u4e0d\u53ef\u4fee\u6539\u3002
offsetWidth\u3001offsetHeight: \u83b7\u53d6\u5143\u7d20\u7684\u6574\u4e2a\u7684\u5bbd\u5ea6\u548c\u9ad8\u5ea6\uff0c\u5305\u62ec\u5185\u5bb9\u533a\u3001\u5185\u8fb9\u8ddd\u548c\u8fb9\u6846\u3002
offsetParent\uff1a\u83b7\u53d6\u5f53\u524d\u5143\u7d20\u7684\u5b9a\u4f4d\u7236\u5143\u7d20\uff0c\u4f1a\u83b7\u53d6\u5230\u79bb\u5f53\u524d\u5143\u7d20\u6700\u8fd1\u7684\u5f00\u542f\u4e86\u5b9a\u4f4d\u7684\u7956\u5148\u5143\u7d20\u3002\u5982\u679c\u6240\u6709\u7684\u7956\u5148\u5143\u7d20\u90fd\u6ca1\u6709\u5f00\u542f\u5b9a\u4f4d\uff0c\u5219\u8fd4\u56debody\u3002
offsetLeft\u3001offsetTop: \u5f53\u524d\u5143\u7d20\u76f8\u5bf9\u4e8e\u5176\u5b9a\u4f4d\u7236\u5143\u7d20\u7684\u6c34\u5e73\u504f\u79fb\u91cf\u3001\u5782\u76f4\u504f\u79fb\u91cf\u3002
scrollHeight\u3001scrollWidth: \u6eda\u52a8\u6587\u6863\u7684\u603b\u9ad8\u5ea6\u3001\u603b\u5bbd\u5ea6\u3002
scrollLeft\u3001scrollTop:  \u83b7\u53d6\u6c34\u5e73\u6eda\u52a8\u6761\u6c34\u5e73\u3001\u5782\u76f4\u79fb\u52a8\u7684\u8ddd\u79bb\u3002

\u5f53\u6ee1\u8db3scrollHeight-scrollTop==clientHeight, \u8bf4\u660e\u5782\u76f4\u6eda\u52a8\u6761\u6eda\u52a8\u5230\u5e95\u4e86\u3002<\/p>\n\n\n\n
\u4e8b\u4ef6\u5bf9\u8c61<\/h2>\n\n\n\n
\u5f53\u4e8b\u4ef6\u7684\u54cd\u5e94\u51fd\u6570\u88ab\u89e6\u53d1\u65f6\uff0c\u6d4f\u89c8\u5668\u6bcf\u6b21\u90fd\u4f1a\u5c06\u4e00\u4e2a\u4e8b\u4ef6\u5bf9\u8c61\u4f5c\u4e3a\u5b9e\u53c2\u4f20\u9012\u8fdb\u54cd\u5e94\u51fd\u6570\u3002\u5728\u4e8b\u4ef6\u5bf9\u8c61\u4e2d\u5c01\u95ed\u4e86\u5f53\u524d\u4e8b\u4ef6\u7684\u4e00\u5207\u4fe1\u606f\uff0c\u6bd4\u5982\u9f20\u6807\u7684\u5750\u6807\u3001\u952e\u76d8\u54ea\u4e2a\u6309\u952e\u88ab\u6309\u4e0b\uff0c\u9f20\u6807\u6eda\u8f6e\u6eda\u52a8\u7684\u65b9\u5411\u3002
\u5728IE8\u4e2d\uff0c\u54cd\u5e94\u51fd\u6570\u88ab\u89e6\u53d1\u65f6\uff0c\u6d4f\u89c8\u5668\u4e0d\u4f1a\u4f20\u9012\u4e8b\u4ef6\u5bf9\u8c61\uff0c\u5728IE8\u53ca\u4ee5\u4e0b\u7684\u6d4f\u89c8\u5668\u4e2d\uff0c\u662f\u5c06\u4e8b\u4ef6\u5bf9\u8c61\u4f5c\u4e3awindow\u5bf9\u8c61\u7684\u5c5e\u6027\u4fdd\u5b58\u7684\u3002
\u4f7f\u7528event=event||window.event;\u8bed\u53e5\u89e3\u51b3\u517c\u5bb9\u6027\u95ee\u9898\u3002<\/p>\n\n\n\n
clientX\u548cclientY\u83b7\u53d6\u9f20\u6807\u76f8\u5bf9\u4e8e\u53ef\u89c1\u7a97\u53e3\u7684X\u3001Y\u5750\u6807\u3002
pageX\u548cpageY\u83b7\u53d6\u9f20\u6807\u76f8\u5bf9\u4e8e\u5f53\u524d\u9875\u9762\u7684\u5750\u6807\u3002IE8\u4e2d\u4e0d\u652f\u6301\u3002<\/p>\n\n\n\n
\u4e8b\u4ef6\u5192\u6ce1<\/h2>\n\n\n\n
\u6307\u4e8b\u4ef6\u5411\u4e0a\u4f20\u5bfc\uff0c\u5f53\u540e\u4ee3\u5143\u7d20\u4e0a\u7684\u4e00\u4e2a\u4e8b\u4ef6\u88ab\u89e6\u53d1\u65f6\uff0c\u5176\u7956\u5148\u5143\u7d20\u7684\u76f8\u540c\u4e8b\u4ef6\uff0c\u4e5f\u4f1a\u88ab\u89e6\u53d1\u3002
\u5927\u90e8\u5206\u60c5\u51b5\u5192\u6ce1\u90fd\u662f\u6709\u7528\u7684\uff0c\u5982\u679c\u4e0d\u5e0c\u671b\u53d1\u884c\u4e8b\u4ef6\u5192\u6ce1\uff0c\u53ef\u4ee5\u901a\u8fc7\u4e8b\u4ef6\u5bf9\u8c61\u6765\u53d6\u6d88\u5192\u6ce1\u3002
event.cancelBubble=true;<\/p>\n\n\n\n
\u4e8b\u4ef6\u59d4\u6d3e<\/p>\n\n\n\n
BOM<\/h2>\n\n\n\n
BOM \u6d4f\u89c8\u5668\u5bf9\u8c61\u6a21\u578b\uff0cBOM\u53ef\u4ee5\u4f7f\u6211\u4eec\u901a\u8fc7JS\u6765\u64cd\u4f5c\u6d4f\u89c8\u5668\u3002
\u5728BOM\u4e2d\u4e3a\u6211\u4eec\u63d0\u4f9b\u4e86\u4e00\u7ec4\u5bf9\u8c61\uff0c\u7528\u6765\u5b8c\u6210\u5bf9\u6d4f\u89c8\u5668\u7684\u64cd\u4f5c\u3002
BOM\u5bf9\u8c61
window\u4ee3\u8868\u7684\u662f\u6574\u4e2a\u6d4f\u89c8\u5668\u7684\u7a97\u53e3\uff0c\u540c\u65f6window\u4e5f\u662f\u7f51\u9875\u4e2d\u7684\u5168\u5c40\u5bf9\u8c61; 
Navigator\uff1a\u4ee3\u8868\u7684\u5f53\u524d\u6d4f\u89c8\u5668\u7684\u4fe1\u606f\uff0c\u901a\u8fc7\u8be5\u5bf9\u8c61\u53ef\u4ee5\u6765\u8bc6\u522b\u4e0d\u540c\u7684\u6d4f\u89c8\u5668
Location\uff1a\u4ee3\u8868\u5f53\u524d\u6d4f\u89c8\u5668\u7684\u5730\u5740\u680f\u4fe1\u606f\uff0c\u901a\u8fc7Location\u53ef\u4ee5\u83b7\u53d6\u5730\u5740\u680f\u4fe1\u606f\uff0c\u6216\u8005\u64cd\u4f5c\u6d4f\u89c8\u5668\u8df3\u8f6c\u9875\u9762\u3002History\uff1a\u4ee3\u8868\u6d4f\u89c8\u5668\u7684\u5386\u53f2\u8bb0\u5f55\uff0c\u53ef\u4ee5\u901a\u8fc7\u8be5\u5bf9\u8c61\u6765\u64cd\u4f5c\u6d4f\u89c8\u5668\u7684\u5386\u53f2\u8bb0\u5f55\u3002\u7531\u4e8e\u9690\u79c1\u539f\u56e0\uff0c\u8be5\u5bf9\u8c61\u4e0d\u80fd\u83b7\u53d6\u5230\u5177\u4f53\u7684\u5386\u53f2\u8bb0\u5f55\uff0c\u53ea\u80fd\u64cd\u4f5c\u6d4f\u89c8\u5668\u5411\u524d\u6216\u5411\u540e\u7ffb\u9875\uff0c\u800c\u4e14\u8be5\u64cd\u4f5c\u53ea\u5728\u5f53\u6b21\u8bbf\u95ee\u65f6\u6709\u6548\u3002
screen\uff1a\u4ee3\u8868\u7528\u6237\u7684\u5c4f\u5e55\u7684\u4fe1\u606f\uff0c\u901a\u8fc7\u8be5\u5bf9\u8c61\u53ef\u4ee5\u83b7\u53d6\u5230\u7528\u6237\u7684\u663e\u793a\u5668\u7684\u76f8\u5173\u7684\u4fe1\u606f<\/p>\n\n\n\n
JS\u9ad8\u7ea7\u4e4b\u6570\u7ec4\u7c7b\u578b\uff1a<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
typeof \u4e0d\u80fd\u5224\u65adnull\u4e0eobject\uff0cobject\u4e0earray\u3002typeof [‘a’,’b’]\uff0c \u8fd4\u56de’object’;<\/p>\n\n\n\n
undefined \u4e0enull\u7684\u533a\u522b\uff1f
\u524d\u8005\u4ee3\u8868\u4ee3\u8868\u4e86\u5b9a\u4e49\u4e86\u672a\u8d4b\u503c; null\u4ee3\u8868\u5b9a\u4e49\u4e86\u5e76\u8d4b\u503c\u4e86\uff0c\u53ea\u662f\u503c\u4e3anull\u3002<\/p>\n\n\n\n
\u4ec0\u4e48\u65f6\u5019\u7ed9\u53d8\u91cf\u8d4b\u503c\u4e3anull\uff1f
null\u7684typeof\u8fd4\u56de\u503c\u4e3aobject\u3002null\u662f\u57fa\u672c\u7c7b\u578b\u3002
\u521d\u59cb\u503c\u8d4b\u503c\u4e3anull,\u8868\u660e\u5c06\u8981\u8d4b\u503c\u4e3a\u5bf9\u8c61\u3002
\u6700\u540e\u8ba9\u4e00\u4e2a\u6307\u5411\u5bf9\u8c61\u7684\u53d8\u91cf\u8d4b\u503c\u4e3anull\uff0c\u8ba9\u5783\u573e\u56de\u6536\u5668\u56de\u6536\u7a7a\u95f4\u3002<\/p>\n\n\n\n
\u4e25\u683c\u533a\u5206\u53d8\u91cf\u7c7b\u578b\u4e0e\u6570\u636e\u7c7b\u578b<\/p>\n\n\n\n
\u51fd\u6570\u7684prototype<\/h2>\n\n\n\n
1.\u51fd\u6570\u7684prototype\u5c5e\u6027
\u6bcf\u4e2a\u51fd\u6570\u90fd\u6709\u4e00\u4e2aprototype\u5c5e\u6027\uff0c\u5b83\u9ed8\u8ba4\u6307\u5411\u4e00\u4e2aObject\u7a7a\u5bf9\u8c61\uff08\u5373\u79f0\u4e3a\uff1a\u539f\u578b\u5bf9\u8c61\uff09\u3002
\u6bcf\u4e2a\u5bf9\u8c61\u4e2d\u6709\u4e00\u4e2a\u5c5e\u6027constructor\uff0c\u5b83\u6307\u5411\u51fd\u6570\u5bf9\u8c61\u3002
2.\u7ed9\u539f\u578b\u5bf9\u8c61\u6dfb\u52a0\u5c5e\u6027\uff08\u4e00\u822c\u90fd\u662f\u65b9\u6cd5\uff09
\u4f5c\u7528\uff1a\u51fd\u6570\u7684\u6240\u6709\u5b9e\u50cf\u5bf9\u8c61\u81ea\u52a8\u62e5\u6709\u539f\u578b\u4e2d\u7684\u5c5e\u6027\uff08\u65b9\u6cd5\uff09<\/p>\n\n\n\n
\u95ed\u5305\u7684\u5e94\u7528\uff1a\u5b9a\u4e49JS\u6a21\u5757
\u5177\u6709\u7279\u5b9a\u529f\u80fd\u7684js\u6587\u4ef6
\u5c06\u6240\u6709\u7684\u6570\u636e\u548c\u529f\u80fd\u90fd\u5c01\u88c5\u5728\u4e00\u4e2a\u51fd\u6570\u5185\u90e8\uff08\u79c1\u6709\u7684\uff09
\u53ea\u5411\u5916\u66b4\u9732\u4e00\u4e2a\u5305\u542bn\u4e2a\u65b9\u6cd5\u7684\u5bf9\u8c61\u6216\u51fd\u6570\u3002
\u6a21\u5757\u7684\u4f7f\u7528\u8005\uff0c\u53ea\u9700\u8981\u901a\u8fc7\u6a21\u5757\u66b4\u9732\u7684\u5bf9\u8c61\u8c03\u7528\u65b9\u6cd5\u6765\u5b9e\u73b0\u5bf9\u5e94\u7684\u529f\u80fd\u3002<\/p>\n\n\n\n
\u5185\u5b58\u6ea2\u51fa\u4e0e\u5185\u5b58\u6cc4\u9732<\/h2>\n\n\n\n
\u5185\u5b58\u6ea2\u51fa\uff1a\u4e00\u79cd\u7a0b\u5e8f\u8fd0\u884c\u51fa\u73b0\u7684\u9519\u8bef\uff0c\u5f53\u7a0b\u5e8f\u8fd0\u884c\u9700\u8981\u7684\u5185\u5b58\u8d85\u8fc7\u4e86\u5269\u4f59\u7684\u5185\u5b58\u65f6\uff0c\u5c31\u51fa\u629b\u51fa\u5185\u5b58\u6ea2\u51fa\u7684\u9519\u8bef\u3002
\u5185\u5b58\u6cc4\u9732\uff1a\u5360\u7528\u7684\u5185\u5b58\u6ca1\u6709\u53ca\u65f6\u91ca\u653e\uff0c\u5185\u5b58\u6cc4\u9732\u79ef\u7d2f\u591a\u4e86\u5c31\u5bb9\u6613\u5bfc\u81f4\u5185\u5b58\u6ea2\u51fa\u3002
\u5e38\u89c1\u7684\u5185\u5b58\u6cc4\u9732:\u610f\u5916\u7684\u5168\u5c40\u53d8\u91cf\u3001\u6ca1\u6709\u53ca\u65f6\u6e05\u7406\u7684\u8ba1\u65f6\u5668\u6216\u56de\u8c03\u51fd\u8f7d\u3001\u95ed\u5305<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5bf9\u8c61 Object.keys(); delete person.name; \/\/\u5220\u9664\u5bf9\u8c61\u4e2d\u7684\u4e00\u4e2a\u5c5e\u6027 \u679a\u4e3e\u5bf9\u8c61 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-2311","post","type-post","status-publish","format-standard","hentry","category-linux"],"_links":{"self":[{"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/posts\/2311"}],"collection":[{"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2311"}],"version-history":[{"count":90,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/posts\/2311\/revisions"}],"predecessor-version":[{"id":2522,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=\/wp\/v2\/posts\/2311\/revisions\/2522"}],"wp:attachment":[{"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2311"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2311"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lcettsg.cn\/code\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2311"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}