{"id":2135,"date":"2017-04-23T17:19:14","date_gmt":"2017-04-23T09:19:14","guid":{"rendered":"http:\/\/www.qdabc.cn\/?p=2135"},"modified":"2017-04-23T17:19:14","modified_gmt":"2017-04-23T09:19:14","slug":"%e5%85%b3%e4%ba%8e%e4%b8%a5%e6%a0%bc%e6%a8%a1%e5%bc%8f%e7%9a%84%e7%ae%80%e5%8d%95%e4%bb%8b%e7%bb%8d","status":"publish","type":"post","link":"http:\/\/www.qdabc.cn\/?p=2135","title":{"rendered":"\u5173\u4e8e\u4e25\u683c\u6a21\u5f0f\u7684\u7b80\u5355\u4ecb\u7ecd"},"content":{"rendered":"
\u6982\u8ff0
\n\u9664\u4e86\u6b63\u5e38\u8fd0\u884c\u6a21\u5f0f\uff0cECMAscript 5\u6dfb\u52a0\u4e86\u7b2c\u4e8c\u79cd\u8fd0\u884c\u6a21\u5f0f\uff1a\u201c\u4e25\u683c\u6a21\u5f0f\u201d\uff08strict \u00a0 mode\uff09\u3002\u987e\u540d\u601d\u4e49\uff0c\u8fd9\u79cd\u6a21\u5f0f\u4f7f\u5f97Javascript\u5728\u66f4\u4e25\u683c\u7684\u6761\u4ef6\u4e0b\u8fd0\u884c\u3002
\n\u8bbe\u7acb\u201d\u4e25\u683c\u6a21\u5f0f\u201c\u7684\u76ee\u7684\uff0c\u4e3b\u8981\u6709\u4ee5\u4e0b\u51e0\u4e2a\uff1a
\n\u6d88\u9664Javascript\u8bed\u6cd5\u7684\u4e00\u4e9b\u4e0d\u5408\u7406\u3001\u4e0d\u4e25\u8c28\u4e4b\u5904\uff0c\u51cf\u5c11\u4e00\u4e9b\u602a\u5f02\u884c\u4e3a;
\n\u6d88\u9664\u4ee3\u7801\u8fd0\u884c\u7684\u4e00\u4e9b\u4e0d\u5b89\u5168\u4e4b\u5904\uff0c\u4fdd\u8bc1\u4ee3\u7801\u8fd0\u884c\u7684\u5b89\u5168\uff1b
\n\u63d0\u9ad8\u7f16\u8bd1\u5668\u6548\u7387\uff0c\u589e\u52a0\u8fd0\u884c\u901f\u5ea6\uff1b
\n\u4e3a\u672a\u6765\u65b0\u7248\u672c\u7684Javascript\u505a\u597d\u94fa\u57ab\u3002
\n\u201c\u4e25\u683c\u6a21\u5f0f\u201d\u4f53\u73b0\u4e86Javascript\u66f4\u5408\u7406\u3001\u66f4\u5b89\u5168\u3001\u66f4\u4e25\u8c28\u7684\u53d1\u5c55\u65b9\u5411\uff0c\u5305\u62ecIE 10\u5728\u5185\u7684\u4e3b\u8981\u6d4f\u89c8\u5668\uff0c\u90fd\u5df2\u7ecf\u652f\u6301\u5b83\uff0c\u8bb8\u591a\u5927\u9879\u76ee\u5df2\u7ecf\u5f00\u59cb\u5168\u9762\u62e5\u62b1\u5b83\u3002
\n\u53e6\u4e00\u65b9\u9762\uff0c\u540c\u6837\u7684\u4ee3\u7801\uff0c\u5728”\u4e25\u683c\u6a21\u5f0f”\u4e2d\uff0c\u53ef\u80fd\u4f1a\u6709\u4e0d\u4e00\u6837\u7684\u8fd0\u884c\u7ed3\u679c\uff1b\u4e00\u4e9b\u5728”\u6b63\u5e38\u6a21\u5f0f”\u4e0b\u53ef\u4ee5\u8fd0\u884c\u7684\u8bed\u53e5\uff0c\u5728”\u4e25\u683c\u6a21\u5f0f”\u4e0b\u5c06\u4e0d\u80fd\u8fd0\u884c\u3002\u638c\u63e1\u8fd9\u4e9b\u5185\u5bb9\uff0c\u6709\u52a9\u4e8e\u66f4\u7ec6\u81f4\u6df1\u5165\u5730\u7406\u89e3Javascript\uff0c\u8ba9\u4f60\u53d8\u6210\u4e00\u4e2a\u66f4\u597d\u7684\u7a0b\u5e8f\u5458\u3002
\n\u8fdb\u5165\u6807\u5fd7
\n\u8fdb\u5165\u201c\u4e25\u683c\u6a21\u5f0f\u201d\u7684\u6807\u5fd7\uff0c\u662f\u4e0b\u9762\u8fd9\u884c\u8bed\u53e5\uff1a
\n“use strict”;
\n\u8001\u7248\u672c\u7684\u6d4f\u89c8\u5668\u4f1a\u628a\u5b83\u5f53\u4f5c\u4e00\u884c\u666e\u901a\u5b57\u7b26\u4e32\uff0c\u52a0\u4ee5\u5ffd\u7565\u3002
\n\u5982\u4f55\u8c03\u7528
\n\u201c\u4e25\u683c\u6a21\u5f0f\u201d\u6709\u4e24\u79cd\u8c03\u7528\u65b9\u6cd5\uff0c\u9002\u7528\u4e8e\u4e0d\u540c\u7684\u573a\u5408\u3002
\n\uff081\uff09 \u9488\u5bf9\u6574\u4e2a\u811a\u672c\u6587\u4ef6
\n\u5c06”use \u00a0 strict”\u653e\u5728\u811a\u672c\u6587\u4ef6\u7684\u7b2c\u4e00\u884c\uff0c\u5219\u6574\u4e2a\u811a\u672c\u90fd\u5c06\u4ee5\u201c\u4e25\u683c\u6a21\u5f0f\u201d\u8fd0\u884c\u3002\u5982\u679c\u8fd9\u884c\u8bed\u53e5\u4e0d\u5728\u7b2c\u4e00\u884c\uff0c\u5219\u65e0\u6548\uff0c\u6574\u4e2a\u811a\u672c\u4ee5\u201c\u6b63\u5e38\u6a21\u5f0f\u201d\u8fd0\u884c\u3002\u5982\u679c\u4e0d\u540c\u6a21\u5f0f\u7684\u4ee3\u7801\u6587\u4ef6\u5408\u5e76\u6210\u4e00\u4e2a\u6587\u4ef6\uff0c\u8fd9\u4e00\u70b9\u9700\u8981\u7279\u522b\u6ce8\u610f\u3002
\n(\u4e25\u683c\u5730\u8bf4\uff0c\u53ea\u8981\u524d\u9762\u4e0d\u662f\u4ea7\u751f\u5b9e\u9645\u8fd0\u884c\u7ed3\u679c\u7684\u8bed\u53e5\uff0c”use strict”\u53ef\u4ee5\u4e0d\u5728\u7b2c\u4e00\u884c\uff0c\u6bd4\u5982\u76f4\u63a5\u8ddf\u5728\u4e00\u4e2a\u7a7a\u7684\u5206\u53f7\u540e\u9762\u3002)
\n<script> \u00a0 \u00a0“use strict”; \u00a0 \u00a0 \u00a0console.log(“\u8fd9\u662f\u4e25\u683c\u6a21\u5f0f\u3002”); \u00a0 \u00a0<\/script> \u00a0 \u00a0<script> \u00a0 \u00a0console.log(“\u8fd9\u662f\u6b63\u5e38\u6a21\u5f0f\u3002”); \u00a0 \u00a0<\/script>
\n\u4e0a\u9762\u7684\u4ee3\u7801\u8868\u793a\uff0c\u4e00\u4e2a\u7f51\u9875\u6587\u4ef6\u4e2d\u4f9d\u6b21\u6709\u4e24\u6bb5Javascript\u4ee3\u7801\u3002\u524d\u4e00\u4e2ascript\u6807\u7b7e\u662f\u4e25\u683c\u6a21\u5f0f\uff0c\u540e\u4e00\u4e2a\u4e0d\u662f\u3002
\n\uff082\uff09\u9488\u5bf9\u5355\u4e2a\u51fd\u6570
\n\u5c06\u201cuse strict\u201d\u653e\u5728\u51fd\u6570\u4f53\u7684\u7b2c\u4e00\u884c\uff0c\u5219\u6574\u4e2a\u51fd\u6570\u4ee5\u201c\u4e25\u683c\u6a21\u5f0f\u201d\u8fd0\u884c\u3002
\nfunction strict(){ \u00a0 \u00a0 \u00a0“use strict”; \u00a0 \u00a0 \u00a0return “\u8fd9\u662f\u4e25\u683c\u6a21\u5f0f\u3002”; \u00a0} \u00a0 \u00a0function notStrict() { \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0return “\u8fd9\u662f\u6b63\u5e38\u6a21\u5f0f\u3002”; \u00a0 \u00a0}
\n\uff083\uff09\u811a\u672c\u6587\u4ef6\u7684\u53d8\u901a\u5199\u6cd5
\n\u56e0\u4e3a\u7b2c\u4e00\u79cd\u8c03\u7528\u65b9\u6cd5\u4e0d\u5229\u4e8e\u6587\u4ef6\u5408\u5e76\uff0c\u6240\u4ee5\u66f4\u597d\u7684\u505a\u6cd5\u662f\uff0c\u501f\u7528\u7b2c\u4e8c\u79cd\u65b9\u6cd5\uff0c\u5c06\u6574\u4e2a\u811a\u672c\u6587\u4ef6\u653e\u5728\u4e00\u4e2a\u7acb\u5373\u6267\u884c\u7684\u533f\u540d\u51fd\u6570\u4e4b\u4e2d\u3002
\n(function (){ \u00a0 \u00a0 \u00a0 \u00a0 “use strict”; \u00a0 \u00a0 \u00a0 \u00a0\/\/ some code here \u00a0 \u00a0 \u00a0})();
\n\u8bed\u6cd5\u548c\u884c\u4e3a\u6539\u53d8
\n\u4e25\u683c\u6a21\u5f0f\u5bf9Javascript\u7684\u8bed\u6cd5\u548c\u884c\u4e3a\uff0c\u90fd\u505a\u4e86\u4e00\u4e9b\u6539\u53d8\u3002
\n\u5168\u5c40\u53d8\u91cf\u663e\u5f0f\u58f0\u660e
\n\u5728\u6b63\u5e38\u6a21\u5f0f\u4e2d\uff0c\u5982\u679c\u4e00\u4e2a\u53d8\u91cf\u6ca1\u6709\u58f0\u660e\u5c31\u8d4b\u503c\uff0c\u9ed8\u8ba4\u662f\u5168\u5c40\u53d8\u91cf\u3002\u4e25\u683c\u6a21\u5f0f\u7981\u6b62\u8fd9\u79cd\u7528\u6cd5\uff0c\u5168\u5c40\u53d8\u91cf\u5fc5\u987b\u663e\u5f0f\u58f0\u660e\u3002
\n“use strict”; \u00a0 \u00a0v = 1; \/\/ \u62a5\u9519\uff0cv\u672a\u58f0\u660e \u00a0 \u00a0for(i = 0; i < 2; i++) { \/\/ \u62a5\u9519\uff0ci\u672a\u58f0\u660e \u00a0}
\n\u56e0\u6b64\uff0c\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0c\u53d8\u91cf\u90fd\u5fc5\u987b\u5148\u7528var\u547d\u4ee4\u58f0\u660e\uff0c\u7136\u540e\u518d\u4f7f\u7528\u3002
\n\u9759\u6001\u7ed1\u5b9a
\nJavascript\u8bed\u8a00\u7684\u4e00\u4e2a\u7279\u70b9\uff0c\u5c31\u662f\u5141\u8bb8\u201c\u52a8\u6001\u7ed1\u5b9a\u201d\uff0c\u5373\u67d0\u4e9b\u5c5e\u6027\u548c\u65b9\u6cd5\u5230\u5e95\u5c5e\u4e8e\u54ea\u4e00\u4e2a\u5bf9\u8c61\uff0c\u4e0d\u662f\u5728\u7f16\u8bd1\u65f6\u786e\u5b9a\u7684\uff0c\u800c\u662f\u5728\u8fd0\u884c\u65f6\uff08runtime\uff09\u786e\u5b9a\u7684\u3002
\n\u4e25\u683c\u6a21\u5f0f\u5bf9\u52a8\u6001\u7ed1\u5b9a\u505a\u4e86\u4e00\u4e9b\u9650\u5236\u3002\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u53ea\u5141\u8bb8\u9759\u6001\u7ed1\u5b9a\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5c5e\u6027\u548c\u65b9\u6cd5\u5230\u5e95\u5f52\u5c5e\u54ea\u4e2a\u5bf9\u8c61\uff0c\u5fc5\u987b\u5728\u7f16\u8bd1\u9636\u6bb5\u5c31\u786e\u5b9a\u3002\u8fd9\u6837\u505a\u6709\u5229\u4e8e\u7f16\u8bd1\u6548\u7387\u7684\u63d0\u9ad8\uff0c\u4e5f\u4f7f\u5f97\u4ee3\u7801\u66f4\u5bb9\u6613\u9605\u8bfb\uff0c\u66f4\u5c11\u51fa\u73b0\u610f\u5916\u3002
\n\u5177\u4f53\u6765\u8bf4\uff0c\u6d89\u53ca\u4ee5\u4e0b\u51e0\u4e2a\u65b9\u9762\u3002
\n\uff081\uff09\u7981\u6b62\u4f7f\u7528with\u8bed\u53e5
\n\u56e0\u4e3awith\u8bed\u53e5\u65e0\u6cd5\u5728\u7f16\u8bd1\u65f6\u5c31\u786e\u5b9a\uff0c\u5c5e\u6027\u5230\u5e95\u5f52\u5c5e\u54ea\u4e2a\u5bf9\u8c61\u3002
\n“use strict”; \u00a0 \u00a0var v \u00a0= 1; \u00a0 \u00a0with (o){ \/\/ \u8bed\u6cd5\u9519\u8bef \u00a0 \u00a0 \u00a0 \u00a0 v = 2; \u00a0 \u00a0}
\n\uff082\uff09\u521b\u8bbeeval\u4f5c\u7528\u57df
\n\u6b63\u5e38\u6a21\u5f0f\u4e0b\uff0cJavascript\u8bed\u8a00\u6709\u4e24\u79cd\u53d8\u91cf\u4f5c\u7528\u57df\uff08scope\uff09\uff1a\u5168\u5c40\u4f5c\u7528\u57df\u548c\u51fd\u6570\u4f5c\u7528\u57df\u3002\u4e25\u683c\u6a21\u5f0f\u521b\u8bbe\u4e86\u7b2c\u4e09\u79cd\u4f5c\u7528\u57df\uff1aeval\u4f5c\u7528\u57df\u3002
\n\u6b63\u5e38\u6a21\u5f0f\u4e0b\uff0ceval\u8bed\u53e5\u7684\u4f5c\u7528\u57df\uff0c\u53d6\u51b3\u4e8e\u5b83\u5904\u4e8e\u5168\u5c40\u4f5c\u7528\u57df\uff0c\u8fd8\u662f\u51fd\u6570\u4f5c\u7528\u57df\u3002\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0ceval\u8bed\u53e5\u672c\u8eab\u5c31\u662f\u4e00\u4e2a\u4f5c\u7528\u57df\uff0c\u4e0d\u518d\u80fd\u591f\u751f\u6210\u5168\u5c40\u53d8\u91cf\u4e86\uff0c\u5b83\u6240\u751f\u6210\u7684\u53d8\u91cf\u53ea\u80fd\u7528\u4e8eeval\u5185\u90e8\u3002
\n“use strict”; \u00a0 \u00a0var x = 2; \u00a0 \u00a0console.info(eval(“var x = 5; x”)); \/\/ 5 \u00a0 \u00a0console.info(x); \/\/ 2
\n\u589e\u5f3a\u7684\u5b89\u5168\u63aa\u65bd
\n\uff081\uff09\u7981\u6b62this\u5173\u952e\u5b57\u6307\u5411\u5168\u5c40\u5bf9\u8c61
\nfunction f(){ \u00a0 \u00a0 \u00a0return !this; \u00a0} \u00a0 \/\/ \u8fd4\u56defalse\uff0c\u56e0\u4e3a\u201cthis\u201d\u6307\u5411\u5168\u5c40\u5bf9\u8c61\uff0c\u201c!this\u201d\u5c31\u662ffalse \u00a0 \u00a0function f(){ \u00a0 \u00a0 \u00a0 \u00a0 “use strict”; \u00a0 \u00a0 \u00a0return !this; \u00a0} \u00a0 \/\/ \u8fd4\u56detrue\uff0c\u56e0\u4e3a\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0cthis\u7684\u503c\u4e3aundefined\uff0c\u6240\u4ee5”!this”\u4e3atrue\u3002
\n\u56e0\u6b64\uff0c\u4f7f\u7528\u6784\u9020\u51fd\u6570\u65f6\uff0c\u5982\u679c\u5fd8\u4e86\u52a0new\uff0cthis\u4e0d\u518d\u6307\u5411\u5168\u5c40\u5bf9\u8c61\uff0c\u800c\u662f\u62a5\u9519\u3002
\nfunction f(){ \u00a0 \u00a0 \u00a0 \u00a0 “use strict”; \u00a0 \u00a0 \u00a0this.a = 1; \u00a0}; \u00a0 \u00a0f();\/\/ \u62a5\u9519\uff0cthis\u672a\u5b9a\u4e49
\n\uff082\uff09\u7981\u6b62\u5728\u51fd\u6570\u5185\u90e8\u904d\u5386\u8c03\u7528\u6808
\nfunction f1(){ \u00a0 \u00a0 \u00a0“use strict”; \u00a0 \u00a0 \u00a0f1.caller; \u00a0 \u00a0\/\/ \u62a5\u9519 \u00a0 \u00a0f1.arguments; \/\/ \u62a5\u9519 \u00a0 \u00a0} \u00a0 \u00a0f1();
\n\u7981\u6b62\u5220\u9664\u53d8\u91cf
\n\u4e25\u683c\u6a21\u5f0f\u4e0b\u65e0\u6cd5\u5220\u9664\u53d8\u91cf\u3002\u53ea\u6709configurable\u8bbe\u7f6e\u4e3atrue\u7684\u5bf9\u8c61\u5c5e\u6027\uff0c\u624d\u80fd\u88ab\u5220\u9664\u3002
\n“use strict”; \u00a0 \u00a0var x; \u00a0 \u00a0delete x; \/\/ \u8bed\u6cd5\u9519\u8bef \u00a0 \u00a0var o = Object.create(null, { \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0x: { \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0value: 1, \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0configurable: true \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0} \u00a0}); \u00a0 \u00a0delete o.x; \/\/ \u5220\u9664\u6210\u529f
\n\u663e\u5f0f\u62a5\u9519
\n\u6b63\u5e38\u6a21\u5f0f\u4e0b\uff0c\u5bf9\u4e00\u4e2a\u5bf9\u8c61\u7684\u53ea\u8bfb\u5c5e\u6027\u8fdb\u884c\u8d4b\u503c\uff0c\u4e0d\u4f1a\u62a5\u9519\uff0c\u53ea\u4f1a\u9ed8\u9ed8\u5730\u5931\u8d25\u3002\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0c\u5c06\u62a5\u9519\u3002
\n“use strict”; \u00a0 \u00a0 var o = {}; \u00a0 \u00a0Object.defineProperty(o, “v”, { value: 1, writable: false }); \u00a0 \u00a0o.v = 2; \/\/ \u62a5\u9519
\n\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0c\u5bf9\u4e00\u4e2a\u4f7f\u7528getter\u65b9\u6cd5\u8bfb\u53d6\u7684\u5c5e\u6027\u8fdb\u884c\u8d4b\u503c\uff0c\u4f1a\u62a5\u9519\u3002
\n“use strict”; \u00a0 \u00a0 var o = { \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0get v() { return 1; } \u00a0 \u00a0 }; \u00a0 \u00a0o.v = 2; \/\/ \u62a5\u9519
\n\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0c\u5bf9\u7981\u6b62\u6269\u5c55\u7684\u5bf9\u8c61\u6dfb\u52a0\u65b0\u5c5e\u6027\uff0c\u4f1a\u62a5\u9519\u3002
\n“use strict”; \u00a0 \u00a0var o = {}; \u00a0 \u00a0Object.preventExtensions(o); \u00a0 \u00a0o.v = 1; \/\/ \u62a5\u9519
\n\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0c\u5220\u9664\u4e00\u4e2a\u4e0d\u53ef\u5220\u9664\u7684\u5c5e\u6027\uff0c\u4f1a\u62a5\u9519\u3002
\n“use strict”; \u00a0 \u00a0delete Object.prototype; \/\/ \u62a5\u9519
\n\u91cd\u540d\u9519\u8bef
\n\u4e25\u683c\u6a21\u5f0f\u65b0\u589e\u4e86\u4e00\u4e9b\u8bed\u6cd5\u9519\u8bef\u3002
\n\uff081\uff09\u5bf9\u8c61\u4e0d\u80fd\u6709\u91cd\u540d\u7684\u5c5e\u6027
\n\u6b63\u5e38\u6a21\u5f0f\u4e0b\uff0c\u5982\u679c\u5bf9\u8c61\u6709\u591a\u4e2a\u91cd\u540d\u5c5e\u6027\uff0c\u6700\u540e\u8d4b\u503c\u7684\u90a3\u4e2a\u5c5e\u6027\u4f1a\u8986\u76d6\u524d\u9762\u7684\u503c\u3002\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0c\u8fd9\u5c5e\u4e8e\u8bed\u6cd5\u9519\u8bef\u3002
\n“use strict”; \u00a0 \u00a0var o = { \u00a0 \u00a0 \u00a0p: 1, \u00a0 \u00a0 \u00a0p: 2 \u00a0}; \/\/ \u8bed\u6cd5\u9519\u8bef
\n\uff082\uff09\u51fd\u6570\u4e0d\u80fd\u6709\u91cd\u540d\u7684\u53c2\u6570
\n\u6b63\u5e38\u6a21\u5f0f\u4e0b\uff0c\u5982\u679c\u51fd\u6570\u6709\u591a\u4e2a\u91cd\u540d\u7684\u53c2\u6570\uff0c\u53ef\u4ee5\u7528arguments[i]\u8bfb\u53d6\u3002\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0c\u8fd9\u5c5e\u4e8e\u8bed\u6cd5\u9519\u8bef\u3002
\n“use strict”; \u00a0 \u00a0function f(a, a, b) { \/\/ \u8bed\u6cd5\u9519\u8bef \u00a0 \u00a0 \u00a0 \u00a0 \u00a0return ; \u00a0 \u00a0 }
\n\u7981\u6b62\u516b\u8fdb\u5236\u8868\u793a\u6cd5
\n\u6b63\u5e38\u6a21\u5f0f\u4e0b\uff0c\u6574\u6570\u7684\u7b2c\u4e00\u4f4d\u5982\u679c\u662f0\uff0c\u8868\u793a\u8fd9\u662f\u516b\u8fdb\u5236\u6570\uff0c\u6bd4\u59820100\u7b49\u4e8e\u5341\u8fdb\u5236\u768464\u3002\u4e25\u683c\u6a21\u5f0f\u7981\u6b62\u8fd9\u79cd\u8868\u793a\u6cd5\uff0c\u6574\u6570\u7b2c\u4e00\u4f4d\u4e3a0\uff0c\u5c06\u62a5\u9519\u3002
\n“use strict”; \u00a0 \u00a0var n = 0100; \/\/ \u8bed\u6cd5\u9519\u8bef
\narguments\u5bf9\u8c61\u7684\u9650\u5236
\narguments\u662f\u51fd\u6570\u7684\u53c2\u6570\u5bf9\u8c61\uff0c\u4e25\u683c\u6a21\u5f0f\u5bf9\u5b83\u7684\u4f7f\u7528\u505a\u4e86\u9650\u5236\u3002
\n\uff081\uff09\u4e0d\u5141\u8bb8\u5bf9arguments\u8d4b\u503c
\n“use strict”; \u00a0 \u00a0arguments++; \/\/ \u8bed\u6cd5\u9519\u8bef \u00a0 \u00a0var obj = { set p(arguments) { } }; \u00a0\/\/ \u8bed\u6cd5\u9519\u8bef \u00a0 \u00a0try { } catch (arguments) { } \u00a0\/\/ \u8bed\u6cd5\u9519\u8bef \u00a0 \u00a0function arguments() { } \u00a0\/\/ \u8bed\u6cd5\u9519\u8bef \u00a0 \u00a0var f = new Function(“arguments”, “‘use strict’; return 17;”); \u00a0\/\/ \u8bed\u6cd5\u9519\u8bef
\n\uff082\uff09arguments\u4e0d\u518d\u8ffd\u8e2a\u53c2\u6570\u7684\u53d8\u5316
\nfunction f(a) { \u00a0 \u00a0a = 2; \u00a0 \u00a0return [a, arguments[0]]; \u00a0} \u00a0 \u00a0f(1); \/\/ \u6b63\u5e38\u6a21\u5f0f\u4e3a[2,2] \u00a0 \u00a0function f(a) { \u00a0 \u00a0“use strict”; \u00a0 \u00a0 \u00a0 \u00a0a = 2; \u00a0 \u00a0return [a, arguments[0]]; \u00a0} \u00a0 \u00a0f(1); \/\/ \u4e25\u683c\u6a21\u5f0f\u4e3a[2,1]
\n\uff083\uff09\u7981\u6b62\u4f7f\u7528arguments.callee
\n\u8fd9\u610f\u5473\u7740\uff0c\u4f60\u65e0\u6cd5\u5728\u533f\u540d\u51fd\u6570\u5185\u90e8\u8c03\u7528\u81ea\u8eab\u4e86\u3002
\n“use strict”; \u00a0 \u00a0var f = function() { return arguments.callee; }; \u00a0 \u00a0f(); \/\/ \u62a5\u9519
\n\u51fd\u6570\u5fc5\u987b\u58f0\u660e\u5728\u9876\u5c42
\n\u5c06\u6765Javascript\u7684\u65b0\u7248\u672c\u4f1a\u5f15\u5165\u201c\u5757\u7ea7\u4f5c\u7528\u57df\u201d\u3002\u4e3a\u4e86\u4e0e\u65b0\u7248\u672c\u63a5\u8f68\uff0c\u4e25\u683c\u6a21\u5f0f\u53ea\u5141\u8bb8\u5728\u5168\u5c40\u4f5c\u7528\u57df\u6216\u51fd\u6570\u4f5c\u7528\u57df\u7684\u9876\u5c42\u58f0\u660e\u51fd\u6570\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u4e0d\u5141\u8bb8\u5728\u975e\u51fd\u6570\u7684\u4ee3\u7801\u5757\u5185\u58f0\u660e\u51fd\u6570\u3002
\n“use strict”; \u00a0 \u00a0if (true) { \u00a0 \u00a0 \u00a0function f() { } \/\/ \u8bed\u6cd5\u9519\u8bef \u00a0 \u00a0} \u00a0 \u00a0for (var i = 0; i < 5; i++) { \u00a0 \u00a0 \u00a0function f2() { } \/\/ \u8bed\u6cd5\u9519\u8bef \u00a0 \u00a0}
\n\u4fdd\u7559\u5b57
\n\u4e3a\u4e86\u5411\u5c06\u6765Javascript\u7684\u65b0\u7248\u672c\u8fc7\u6e21\uff0c\u4e25\u683c\u6a21\u5f0f\u65b0\u589e\u4e86\u4e00\u4e9b\u4fdd\u7559\u5b57\uff1aimplements, interface, let, package, \u00a0 private, protected, public, static, yield\u3002
\n\u4f7f\u7528\u8fd9\u4e9b\u8bcd\u4f5c\u4e3a\u53d8\u91cf\u540d\u5c06\u4f1a\u62a5\u9519\u3002
\nfunction package(protected) { \/\/ \u8bed\u6cd5\u9519\u8bef \u00a0 \u00a0 \u00a0“use strict”; \u00a0 \u00a0 \u00a0var implements; \/\/ \u8bed\u6cd5\u9519\u8bef \u00a0 \u00a0}
\n\u6b64\u5916\uff0cECMAscript\u7b2c\u4e94\u7248\u672c\u8eab\u8fd8\u89c4\u5b9a\u4e86\u53e6\u4e00\u4e9b\u4fdd\u7559\u5b57\uff08class, enum, export, extends, import, \u00a0 super\uff09\uff0c\u4ee5\u53ca\u5404\u5927\u6d4f\u89c8\u5668\u81ea\u884c\u589e\u52a0\u7684const\u4fdd\u7559\u5b57\uff0c\u4e5f\u662f\u4e0d\u80fd\u4f5c\u4e3a\u53d8\u91cf\u540d\u7684\u3002<\/div>\n
<\/div>\n
<\/div>\n

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