{"id":4747,"date":"2015-04-18T23:13:44","date_gmt":"2015-04-18T15:13:44","guid":{"rendered":"http:\/\/www.zhangxinxu.com\/wordpress\/?p=4747"},"modified":"2015-04-18T23:26:11","modified_gmt":"2015-04-18T15:26:11","slug":"understand-web-front-undefined-behavior","status":"publish","type":"post","link":"https:\/\/www.zhangxinxu.com\/wordpress\/2015\/04\/understand-web-front-undefined-behavior\/","title":{"rendered":"\u4e86\u89e3web\u524d\u7aef\u9886\u57df\u7684undefined behavior\u672a\u5b9a\u4e49\u884c\u4e3a"},"content":{"rendered":"<p>by <a href=\"http:\/\/www.zhangxinxu.com\/\">zhangxinxu<\/a> from <a href=\"http:\/\/www.zhangxinxu.com\/\">http:\/\/www.zhangxinxu.com<\/a><br \/>\n\u672c\u6587\u5730\u5740\uff1a<a href=\"http:\/\/www.zhangxinxu.com\/wordpress\/?p=4747\">http:\/\/www.zhangxinxu.com\/wordpress\/?p=4747<\/a><\/p>\n<h3>\u4e00\u3001\u672c\u6587\u4e3a\u8d85\u77ed\u7bc7<\/h3>\n<p><strong>undefined behavior<\/strong>\u53ef\u4ee5\u7b97\u662f\u8ba1\u7b97\u673a\u4e16\u754c\u4e2d\u7279\u6709\u7684\u4e00\u4e2a\u540d\u5b57\uff0c\u4e2d\u6587\u610f\u601d\u662f\u201c\u672a\u5b9a\u4e49\u884c\u4e3a\u201d\uff0c<a href=\"http:\/\/en.wikipedia.org\/wiki\/Undefined_behavior\" target=\"_blank\">\u7ef4\u57fa\u767e\u79d1\u4e0a\u6709\u89e3\u91ca<\/a>\u3002\u5728C\u4ee5\u53caC++\u8bed\u8a00\u4e2d\uff0c\u8fd9\u53ef\u4ee5\u7b97\u662f\u4e00\u4e2a\u6bd4\u8f83\u660e\u786e\u7684\u6982\u5ff5\uff1a<\/p>\n<blockquote><p>undefined behavior: use of an unspecified value, or other behavior where this International Standard provides two or more possibilities and imposes no further requirements on which is chosen in any instance<\/p><\/blockquote>\n<p>\u5b9e\u9645\u4e0a\uff0c\u5728web\u524d\u7aef\u9886\u57df\uff0c\u4e5f\u6709undefined behavior\u672a\u5b9a\u4e49\u884c\u4e3a\uff0c\u4e14\u5e7f\u6cdb\u7a0b\u5ea6\u8fdc\u8fdc\u8d85\u51fa\u4e86\u4f60\u7684\u60f3\u8c61\u3002<\/p>\n<p>undefined behavior\u4eceweb\u6807\u51c6\u51fa\u73b0\u4e4b\u540e\uff0c\u5b9e\u9645\u4e0a\u5c31\u5e7f\u6cdb\u5b58\u5728web\u7f51\u9875\u524d\u7aef\u6280\u672f\u4e2d\uff0c\u6211\u4eec\u5f88\u591a\u65f6\u5019\u9047\u5230\u7684\u6d4f\u89c8\u5668\u517c\u5bb9\u6027\u95ee\u9898\uff0c\u53ef\u80fd\u5c31\u5c5e\u4e8eundefined behavior\u3002\u7c97\u8bfb\u8fd9\u53e5\u8bdd\uff0c\u597d\u50cfweb\u6807\u51c6\u5e72\u4e86\u4ec0\u4e48\u574f\u4e8b\u3002\u5b9e\u9645\u4e0a\u5e76\u4e0d\u662f\uff0c\u5728web\u6807\u51c6\u6ca1\u51fa\u73b0\u4e4b\u524d\uff0c\u5f88\u591a\u6d4f\u89c8\u5668\u90fd\u6709\u5404\u81ea\u7684\u884c\u4e3a\u8868\u73b0\uff0c\u6211\u4eec\u79f0\u4e4b\u4e3a\u517c\u5bb9\u6027\u95ee\u9898\uff0c\u4f46\u662f\uff0c\u8fd9\u4e0d\u80fd\u79f0\u4e4b\u4e3aundefined behavior\u672a\u5b9a\u4e49\u884c\u4e3a\u3002\u4e3a\u4ec0\u4e48\u5462\uff1f\u56e0\u4e3a\u6ca1\u6709\u4e00\u4e2a\u6807\u51c6\u4f5c\u4e3a\u4f9d\u636e\uff0c\u672a\u5b9a\u4e49\u884c\u4e3a\u4e4b\u6240\u4ee5\u79f0\u4e4b\u4e3a\u672a\u5b9a\u4e49\u884c\u4e3a\uff0c\u5c31\u662f\u56e0\u5176\u6e38\u79bb\u4e8e\u6807\u51c6\u4e4b\u5916\u3002\u6211\u4eec\u6362\u79cd\u8bf4\u6cd5\u53ef\u80fd\u66f4\u597d\u7406\u89e3\uff0cundefined behavior\u53c8\u53ef\u4ee5\u7406\u89e3\u4e3a\u6cd5\u5f8b\u7a7a\u767d\u3002\u4f60\u8981\u5148\u6709\u6cd5\u5f8b\uff0c\u624d\u6709\u6cd5\u5f8b\u7a7a\u767d\u3002\u5728\u6cd5\u5f8b\u754c\uff0c\u5178\u578b\u7684\u672a\u5b9a\u4e49\u884c\u4e3a\u5c31\u662f\u300c\u540c\u6027\u6027\u4fb5\u300d\u3002\u6240\u4ee5\u4f2a\u5a18\u6df1\u591c\u66f4\u4e0d\u80fd\u72ec\u884c\uff0c\u5426\u5219\u88ab\u5360\u4e86\u4fbf\u5b9c\u8fd8\u4e0d\u80fd\u6cd5\u5236\u4e86\u8272\u72fc\uff0c\u4e8f\u5927\u4e86\u3002<\/p>\n<p>web\u6807\u51c6\u7684\u51fa\u73b0\u8ba9\u6d4f\u89c8\u5668\u95f4\u7684\u884c\u4e3a\u8d8a\u6765\u8d8a\u7edf\u4e00\uff0c\u505a\u51fa\u4e86\u975e\u5e38\u91cd\u8981\u7684\u8d21\u732e\u3002\u57fa\u672c\u4e0a\uff0c\u5728\u73b0\u4ee3\u6d4f\u89c8\u5668\u4e2d\uff0c\u652f\u6301\u5148\u540e\u8fd9\u4e2a\u4e0d\u7b97\uff0c\u5c31\u4e00\u822c\u7684CSS\u6216JS\uff0c\u6211\u4eec\u901a\u5e38\u4f7f\u7528\u90fd\u6ca1\u6709\u517c\u5bb9\u6027\u95ee\u9898\u3002\u4f46\u662f\uff0c\u51e1\u4e8b\u53ef\u80fd\u4f1a\u53d1\u751f\u7684\u4e8b\u60c5\u4e00\u5b9a\u4f1a\u53d1\u751f\u3002\u5bf9\u4e8eIE\/Chrome\/FireFox\u4e09\u5927\u5bb6\u65cf\u6d4f\u89c8\u5668\uff0c\u4e00\u65e6\u53d1\u73b0\u67d0\u4e2a\u6d4f\u89c8\u5668\u8ddf\u5176\u4ed6\u4e24\u4e2a\u4e0d\u4e00\u6837\uff0c\u6211\u4eec\u7684\u53cd\u5e94\u53ef\u80fd\u4f1a\u8fd9\u6837\uff1a<\/p>\n<ol>\n<li>\u5982\u679c\u662fIE\u4f7f\u6027\u5b50\uff0c\u548cChrome\u548cFireFox\u8868\u73b0\u90fd\u4e0d\u4e00\u6837\uff0c\u6211\u4eec\u4f1a\u8ba4\u4e3aIE\u51fabug\u4e86\uff01 <img decoding=\"async\" src=\"http:\/\/mat1.gtimg.com\/www\/mb\/images\/face\/36.gif\" align=\"absmiddle\"><\/li>\n<li>\u5982\u679c\u662fChrome\u800d\u5927\u724c\uff0c\u8ddfIE\u548cFireFox\u8868\u73b0\u4e0d\u4e00\u6837\uff0c\u6211\u4eec\u4f1a\u66ffChrome\u8fa9\u62a4(\u5c31\u50cf\u4e0b\u9762\u8fd9\u6837\u7684\u8bc4\u8bba\uff0c\u6765\u81ea<a href=\"http:\/\/www.zhangxinxu.com\/wordpress\/2015\/01\/chrome-absolute-display-visibility-render-bug\/\">\u8fd9\u91cc<\/a>)<br \/>\n<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/image.zhangxinxu.com\/image\/blog\/201504\/2015-04-18_221021.png\" width=\"806\" height=\"128\" alt=\"\u4e3aChrome\u6d4f\u89c8\u5668\u8fa9\u62a4\" class=\"alignnone\" \/><\/li>\n<li>\u5982\u679c\u662fFireFox\u95f9\u813e\u6c14\uff0c\u8ddfIE\u548cChrome\u8868\u73b0\u4e0d\u4e00\u6837\uff0c\u6211\u4eec\u4f1a\u7565\u540c\u60c5\uff0cFireFox\u4f60\u600e\u4e48\u4e86\uff0c\u4f60\u4e0d\u518d\u632f\u4f5c\u600e\u4e48\u8ddf\u5176\u4ed6\u6d4f\u89c8\u5668\u6297\u8861\u554a\uff01<\/li>\n<\/ol>\n<p><img decoding=\"async\" src=\"http:\/\/mat1.gtimg.com\/www\/mb\/images\/face\/21.gif\" align=\"absmiddle\"><\/p>\n<p>\u4e00\u65e6\u8d27\u6bd4\u4e09\u5bb6\uff0c\u53d1\u73b0\u67d0\u4e00\u6237\u8ddf\u5176\u4ed6\u6240\u6709\u4eba\u5bb6\u90fd\u4e0d\u4e00\u6837\uff0c\u5176\u5b9e\uff0c\u6211\u4eec\u66f4\u591a\u5730\u662f\u8ba4\u4e3a\u8fd9\u4e2a\u641e\u7279\u6b8a\u7684\u6d4f\u89c8\u5668\u51fabug\u4e86\uff01\u9119\u4eba\u5176\u5b9e\u5c31\u8fd9\u4e48\u8ba4\u4e3a\u4e86\uff0c\u6c57~<\/p>\n<p>\u4f46\u662f\uff0c\u81ea\u52a8\u4e86\u89e3\u4e86undefined behavior\u672a\u5b9a\u4e49\u884c\u4e3a\u4e4b\u540e\uff0c\u6211\u53d1\u73b0\u6211\u4e4b\u524d\u7684\u8ba4\u77e5\u6709\u4e9b\u72ed\u9698\u4e86\u3002\u201c<a href=\"http:\/\/www.zhangxinxu.com\/wordpress\/2015\/01\/chrome-absolute-display-visibility-render-bug\/\">Chrome absolute\u7edd\u5bf9\u5b9a\u4f4ddisplay\/visibility\u6e32\u67d3bug<\/a>\u201d\u4e00\u6587\u4e2d\u63d0\u5230\u7684\u95ee\u9898\u53ef\u80fd\u5e76\u4e0d\u662fbug\uff0c\u800c\u53ea\u662f\u201c\u672a\u5b9a\u4e49\u884c\u4e3a\u201d\uff0c\u4e5f\u5c31\u662fweb\u6807\u51c6\u5e76\u6ca1\u6709\u8be6\u7ec6\u63cf\u8ff0\u6b64\u65f6\u7684\u884c\u4e3a\u8868\u73b0\uff0c\u800cChrome\u6d4f\u89c8\u5668\u6839\u636e\u81ea\u5df1\u7684\u7406\u89e3\u6216\u8005\u89c4\u5219\u53bb\u5904\u7406\u4e86\uff08\u65e0\u91cd\u7ed8\u3001\u66f4\u9ad8\u6027\u80fd\uff09\uff0c\u4eba\u5bb6\u53ea\u662f\u5728\u89c4\u5219\u5141\u8bb8\u8303\u56f4\u5185\u505a\u4e86\u70b9\u4e2a\u6027\u7684\u4e8b\u60c5\uff0c\u600e\u4e48\u80fd\u5c31\u53eb\u4eba\u5bb6bug\u5462\uff01\uff01\u5f53\u7136\uff0c\u53ef\u80fd\u5c5e\u4e8e\u672a\u5b9a\u4e49\u884c\u4e3a\uff0c\u53ea\u662f\u53ef\u80fd\uff0c\u6211\u8fd8\u662f\u89c9\u5f97\u662fChrome\u6d4f\u89c8\u5668\u81ea\u5df1\u7684\u95ee\u9898\u3002<\/p>\n<p>\u4f46\u662f\uff0c\u4e0b\u9762\u8fd9\u4e2a\u6d4f\u89c8\u5668\u5dee\u5f02\u73b0\u8c61\uff0c\u621199%\u786e\u4fe1\u662f\u201c\u672a\u5b9a\u4e49\u884c\u4e3a\u201d\uff0c\u4e00\u8d77\u6765\u770b\u4e0b\u5427\uff01<\/p>\n<h3>\u4e8c\u3001FireFox\u6d4f\u89c8\u5668\u4e0b\u201c\u672a\u5b9a\u4e49\u884c\u4e3a\u201d\u4e00\u5219<\/h3>\n<p>\u6211\u4eec\u90fd\u77e5\u9053\uff0cCSS\u4e2d\u6709\u4e2a\u4f2a\u7c7b<code>:active<\/code>, IE9+\u4e4b\u540e\u7684\u6d4f\u89c8\u5668\u884c\u4e3a\u8868\u73b0\u975e\u5e38\u7edf\u4e00\uff0c\u9f20\u6807\u6309\u4e0b\uff0c\u6267\u884c<code>:active<\/code>\u4f2a\u7c7b\u5bf9\u5e94\u7684CSS\u6837\u5f0f\uff0c\u9f20\u6807\u62ac\u8d77\u8fd8\u539f\u3002\u4e8e\u662f\uff0c\u6211\u4eec\u53ef\u80fd\u5f88\u8f7b\u677e\u5730\u5b9e\u73b0\u9f20\u6807\u6309\u4e0b\u7684\u6548\u679c\uff08\u8001IE\u6d4f\u89c8\u5668\u5931\u7126\u6548\u679c\u6837\u5f0f\u8fd8\u539f\uff09\u3002\u4f8b\u5982\uff0c\u4e0b\u9762\u8fd9\u4e2a\u7ea2\u8272\u533a\u57df\uff0c\u6309\u4e0b\u4f1a\u53d8\u8272\uff0c\u62ac\u8d77\u53c8\u6062\u590d\uff1a<\/p>\n<style>.active-btn{display: inline-block; font-size:14px; background-color:#cd0000; color:#fff; padding:5px 10px;}.active-btn:hover{text-decoration:none; color:#fff;}.active-btn:active {background-color:#be0000;color:#333;}<\/style>\n<p><a href=\"javascript:\" class=\"active-btn\">\u6309\u6211<\/a><\/p>\n<p>\u8fd9\u4e2a\u4f2a\u7c7b\u662f\u6ca1\u6709\u4efb\u4f55\u95ee\u9898\u7684\uff0c\u4f46\u662f\uff0c\u5f53\u906d\u9047\u5176\u4ed6\u4e00\u4e9b\u5904\u7406\u7684\u65f6\u5019\uff0c\u4e8b\u60c5\u5c31\u4f1a\u53d8\u5f97\u4e0d\u4e00\u6837\uff0c\u4ec0\u4e48\u4e8b\u60c5\u5462\uff1f<\/p>\n<p>\u5047\u8bbe\u6b64\u6309\u94ae\u7684DOM\u5bf9\u8c61\u53d8\u91cf\u540d\u4e3a<code>button<\/code>, \u5219\u6211\u4eec\u5199\u4e00\u4e2a\u5c0f\u811a\u672c\uff0c\u4f8b\u5982\uff1a<\/p>\n<div class=\"zxx_code\">\n<pre>button.addEventListener(\"mousedown\", function(event) {\n    <span style=\"color:green;\">\/\/ \u6b64\u5904\u7701\u7565N\u884c<\/span>\n    event.preventDefault();\t\n});<\/pre>\n<\/div>\n<p>\u4e0a\u9762\u8fd9\u6bb5\u811a\u672c\uff0c\u8fde\u4e0d\u662f\u5708\u5b50\u91cc\u7684\u6211\u7684\u592b\u4eba\u90fd\u77e5\u9053\u610f\u601d\uff0c\u5c31\u662f\u6309\u94ae\u5728\u6309\u4e0b\u7684\u65f6\u5019\uff0c\u963b\u6b62\u9ed8\u8ba4\u884c\u4e3a\uff08\u8fd9\u6837\u62d6\u52a8\u7684\u65f6\u5019\u5c31\u4f1a\u5f88\u6d41\u7545\uff09\u3002<\/p>\n<p>\u770b\u4f3c\u5e73\u6de1\u65e0\u5947\uff0c\u4f46\u662f\uff0c\u6700\u540e\u53d1\u751f\u4e86\u4e0d\u548c\u8c10\u7684\u4e8b\u60c5\uff1aIE\u548cChrome\u6d4f\u89c8\u5668\uff0c<code>:active<\/code>\u4f2a\u7c7b\u4f9d\u7136\u6d3b\u8e66\u4e71\u8df3\uff0c\u4f46\u662f\uff0cFireFox\u6d4f\u89c8\u5668\u7684<code>:active<\/code>\u4f2a\u7c7b\u6837\u5f0f\u9635\u4ea1\u4e86\uff0c\u9f20\u6807\u6309\u4e0b\u53bb\u6ca1\u6709UI\u53d8\u5316\uff01<\/p>\n<p>\u767e\u95fb\u4e0d\u5982\u4e00\u89c1\uff0c\u60a8\u53ef\u4ee5\u72e0\u72e0\u5730\u70b9\u51fb\u8fd9\u91cc\uff1a<a class=\"a_link\" href=\"http:\/\/www.zhangxinxu.com\/study\/201504\/firefox-mousedown-active-preventdefault.html\" target=\"_blank\">FireFox mousedown preventDefault\u4f7factive\u4f2a\u7c7b\u5931\u6548Demo<\/a><\/p>\n<p>demo\u9875\u9762\u4e2d\uff0c\u4e0a\u4e00\u4e2a\u6309\u94ae\u5c31\u662f\u5f88\u666e\u901a\u7684CSS\u6309\u94ae\uff0c\u4e0b\u9762\u4e00\u4e2a\u6309\u94ae\uff0cCSS\u90e8\u5206\u8ddf\u4e0a\u9762\u4e00\u6837\uff0c\u4f46\u662f\uff0c\u5b9e\u9645\u4e0a\uff0c\u5176\u88abJS\u7ed9\u73b7\u6c61\u4e86\u4e0b\uff0c\u7ed1\u5b9a\u4e86\u4e2a<code>mousedown<\/code>\u4e8b\u4ef6\uff0c\u540c\u65f6\u8fd8\u963b\u6b62\u4e86\u9ed8\u8ba4\u884c\u4e3a\u3002\u4f46\u662f\uff0cIE\u548cChrome\u6d4f\u89c8\u5668\uff0c\u4e0a\u9762\u4e24\u4e2a\u6309\u94ae\u70b9\u51fb\u90fd\u5f88\u5f00\u5fc3\uff0c\u4f46\u662f\uff0cFireFox\u6d4f\u89c8\u5668\uff0c\u4e0b\u9762\u8fd9\u4e2a\u6309\u94ae\uff0c\u6309\u4e0b\u6548\u679c\u6728\u6709\u5566\uff01<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/image.zhangxinxu.com\/image\/blog\/201504\/2015-04-18_225713.png\" width=\"325\" height=\"212\" alt=\"FireFox\u6d4f\u89c8\u5668\u6309\u4e0b\u6ca1\u6709\u6548\u679c\" class=\"alignnone\" \/><\/p>\n<p>\u8fd9\u91cc\uff0cFireFox\u548cIE, Chrome\u6d4f\u89c8\u5668\u8868\u73b0\u4e0d\u4e00\u6837\uff0c\u8fd9\u662fFireFox\u6d4f\u89c8\u5668\u7684bug\u5417\uff1f\u4eb2\uff0c\u8fd9\u53ef\u4e0d\u662fbug, \u800c\u662fw3\u89c4\u8303\u4e0a\u5e76\u6ca1\u6709\u5bf9\u8fd9\u79cd\u573a\u666f\u7684\u5177\u4f53\u63cf\u8ff0\uff0c\u6240\u4ee5\uff0cFireFox\u8ba4\u4e3a<code>active<\/code>\u53d1\u751f\u5728<code>mousedown<\/code>\u4e8b\u4ef6\u4e4b\u540e\uff0c\u4f60\u4e5f\u4e0d\u80fd\u8bf4\u4ed6\u4ec0\u4e48\uff0c\u5bf9\u5427\u3002\u5c31\u597d\u50cf\u7bee\u7403\u6bd4\u8d5b\uff0c\u6211\u9886\u5148\uff0c\u6211\u5c31\u7528\u5b8c24\u79d2\u518d\u51fa\u624b\uff0c\u600e\u4e48\u7740\uff0c\u4f60\u6765\u54ac\u6211\u554a\uff01<\/p>\n<p>\u5bf9\u5427\uff0c\u4f60\u4e0d\u80fd\u8bf4FireFox\u6d4f\u89c8\u5668\u7684\u4e0d\u662f\uff0c\u6700\u591a\u6211\u4eec\u9053\u5fb7\u4e0a\u8c34\u8d23\u5979\uff0c\u56de\u5934\u5462\uff0c\u6211\u4eec\u8fd8\u5f97\u8001\u8001\u5b9e\u5b9e\u60f3\u529e\u6cd5\u6253\u4e2a\u5c0f\u5e03\u4e01\uff0c\u4f8b\u5982\uff0c\u5224\u65ad\u662fFireFox\u6d4f\u89c8\u5668\uff0c\u7136\u540e\u52a0\u4e2a\u7c7b\u540dactive(\u89c1\u4e0b\u4ee3\u7801\u7ea2\u8272\u9ad8\u4eae)(\u79fb\u9664\u7c7b\u540dactive\u811a\u672c\u7565)\uff0cCSS\u4e2d\u518d\u591a\u4e2a<code>.active<\/code>\u7684\u6837\u5f0f\uff1a<\/p>\n<div class=\"zxx_code\">\n<pre>button.addEventListener(\"mousedown\", function(event) {\n    <span style=\"color:green;\">\/\/ \u6b64\u5904\u7701\u7565N\u884c<\/span>\n    <span style=\"color:#cd0000;\">if (typeof document.mozHidden != \"undefined\") this.classList.add(\"active\");<\/span>\n    event.preventDefault();\t\n});<\/pre>\n<\/div>\n<h3>\u4e09\u3001\u7ed3\u8bed<\/h3>\n<p>\u6628\u665a\u770b\u4e86\u90e8\u7535\u5f71\u300a\u5730\u7403\u4e0a\u7684\u661f\u661f\u300b\uff0c\u4e0a\u5e1d\u5173\u4e0a\u4e00\u6247\u95e8\uff0c\u4e5f\u4f1a\u5173\u6389\u53e6\u5916\u4e00\u6247\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/image.zhangxinxu.com\/image\/blog\/201504\/earth-star.jpg\" width=\"240\" height=\"169\" alt=\"\u5730\u7403\u4e0a\u7684\u661f\u661f\" class=\"alignnone\" \/><\/p>\n<p>\u6211\u5e73\u65f6\u8bdd\u5c11\uff0c\u8ddf\u8bdd\u75e8\u76f8\u52a0\uff0c\u6b63\u597d100%\u3002\u4f46\u662f\uff0c\u5199\u4e1c\u897f\u65f6\u5019\uff0c\u8bdd\u5374\u5f88\u591a\u3002\u4e0b\u7b14\u5199\u6807\u9898\u65f6\u5019\uff0c\u6211\u771f\u89c9\u5f97\u51e0\u767e\u5b57\u5c31\u7ed3\u675f\u4e86\uff0c\u7ed3\u679c\uff0c\u4e00\u5199\u4e0d\u53ef\u6536\u62fe\uff0c\u4ece\u9884\u60f3\u7684\u8d85\u77ed\u7bc7\u53d8\u6210\u4e86\u77ed\u7bc7\u51fa\u5934\u4e00\u70b9\u70b9\u3002<\/p>\n<p>\u64e6\uff0c\u6211\u5728\u5e72\u4ec0\u4e48\uff0c\u53c8\u5728\u778e\u626f\u6de1\u4e86\u3002\u901f\u901f\u7ed3\u8bed\u2026\u2026<\/p>\n<p>\u7ed3\u8bed\u5c31\u662f\u6ca1\u6709\u7ed3\u8bed\uff01<\/p>\n<p>\u672c\u6587\u4e3a\u539f\u521b\u6587\u7ae0\uff0c\u5305\u542b\u811a\u672c\u884c\u4e3a\uff0c\u4f1a\u7ecf\u5e38\u66f4\u65b0\u77e5\u8bc6\u70b9\u4ee5\u53ca\u4fee\u6b63\u4e00\u4e9b\u9519\u8bef\uff0c\u56e0\u6b64\u8f6c\u8f7d\u8bf7\u4fdd\u7559\u539f\u51fa\u5904\uff0c\u65b9\u4fbf\u6eaf\u6e90\uff0c\u907f\u514d\u9648\u65e7\u9519\u8bef\u77e5\u8bc6\u7684\u8bef\u5bfc\uff0c\u540c\u65f6\u6709\u66f4\u597d\u7684\u9605\u8bfb\u4f53\u9a8c\u3002<br \/>\n\u672c\u6587\u5730\u5740\uff1a<a href=\"http:\/\/www.zhangxinxu.com\/wordpress\/?p=4747\">http:\/\/www.zhangxinxu.com\/wordpress\/?p=4747<\/a><\/p>\n<p>\uff08\u672c\u7bc7\u5b8c\uff09<\/p>\n","protected":false},"excerpt":{"rendered":"<p>undefined behavior\u53ef\u4ee5\u7b97\u662f\u8ba1\u7b97\u673a\u4e16\u754c\u4e2d\u7279\u6709\u7684\u4e00\u4e2a\u540d\u5b57\uff0c\u4e2d\u6587\u610f\u601d\u662f\u201c\u672a\u5b9a\u4e49\u884c\u4e3a\u201d\uff0c\u7ef4\u57fa\u767e\u79d1\u4e0a\u6709\u89e3\u91ca\u3002\u5728C\u4ee5\u53caC++\u8bed\u8a00\u4e2d\uff0c\u8fd9\u53ef\u4ee5\u7b97\u662f\u4e00\u4e2a\u6bd4\u8f83\u660e\u786e\u7684\u6982\u5ff5\u3002<\/p>\n<p>\u5b9e\u9645\u4e0a\uff0c\u5728web\u524d\u7aef\u9886\u57df\uff0c\u4e5f\u6709undefined behavior\u672a\u5b9a\u4e49\u884c\u4e3a\uff0c\u4e14\u5e7f\u6cdb\u7a0b\u5ea6\u8fdc\u8fdc\u8d85\u51fa\u4e86\u4f60\u7684\u60f3\u8c61\u3002<br \/>\nundefined behavior\u4eceweb\u6807\u51c6\u51fa\u73b0\u4e4b\u540e\uff0c\u5b9e\u9645\u4e0a\u5c31\u5e7f\u6cdb\u5b58\u5728web\u7f51\u9875\u524d\u7aef\u6280\u672f\u4e2d\uff0c\u6211\u4eec\u5f88\u591a\u65f6\u5019\u9047\u5230\u7684\u6d4f\u89c8\u5668\u517c\u5bb9\u6027\u95ee\u9898\uff0c\u53ef\u80fd\u5c31\u5c5e\u4e8e\u2026\u2026<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[296,987,379,988,507],"_links":{"self":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/4747"}],"collection":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/comments?post=4747"}],"version-history":[{"count":0,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/4747\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/media?parent=4747"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/categories?post=4747"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/tags?post=4747"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}