{"id":185,"date":"2017-05-18T20:32:33","date_gmt":"2017-05-18T12:32:33","guid":{"rendered":"http:\/\/zouyang1230.com\/blog\/?p=185"},"modified":"2020-10-28T22:46:57","modified_gmt":"2020-10-28T14:46:57","slug":"%e6%b5%81%e7%a8%8b%e6%8e%a7%e5%88%b6%e7%9a%84%e5%ba%95%e5%b1%82%e5%ae%9e%e7%8e%b0","status":"publish","type":"post","link":"http:\/\/www.imzouyang.com\/blog\/archives\/185.html","title":{"rendered":"\u6d41\u7a0b\u63a7\u5236\u7684\u5e95\u5c42\u5b9e\u73b0"},"content":{"rendered":"<p>\u4ee3\u7801\u88ab\u7f16\u8bd1\u540e\uff0c\u6307\u4ee4\u4e00\u6761\u63a5\u7740\u4e00\u6761\u987a\u5e8f\u7684\u6267\u884c\uff0c\u662f\u6211\u4eec\u8fc7\u53bb\u5e38\u89c1\u7684\u76f4\u7ebf\u4ee3\u7801\u7684\u884c\u4e3a\u3002<br \/>\n\u73b0\u5728\u7684\u9ad8\u7ea7\u8bed\u8a00\u4e2d\uff0c\u52a0\u5165\u4e86\u6d41\u7a0b\u63a7\u5236\u8bed\u53e5\u3002\u6bd4\u5982\u6761\u4ef6\u8bed\u53e5\u3001\u5faa\u73af\u8bed\u53e5\u548c\u5206\u652f\u8bed\u53e5\u3002<br 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\/>\n3\u3001\u53ef\u4ee5\u6709\u6761\u4ef6\u7684\u4f20\u9001\u6570\u636e\u3002<\/p><\/blockquote>\n<p>&nbsp;<\/p>\n<p>\u63a7\u5236\u6d41\u662f\u5b9e\u73b0\u6709\u6761\u4ef6\u884c\u4e3a\u7684\u66f4\u901a\u7528\u548c\u66f4\u5e38\u89c1\u7684\u65b9\u6cd5\uff0c\u5982\u4f55\u6539\u53d8\u63a7\u5236\u6d41\uff1a<br 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go to \u8bed\u53e5\u3002<br \/>\nswitch\u8bed\u53e5\u53ef\u4ee5\u6839\u636e\u4e00\u4e2a\u6574\u6570\u7d22\u5f15\u503c\u8fdb\u884c\u591a\u91cd\u5206\u652f\u3002\u5904\u7406\u5177\u6709\u591a\u79cd\u53ef\u80fd\u7ed3\u679c\u7684\u6d4b\u8bd5\u65f6\uff0c\u8fd9\u79cd\u8bed\u53e5\u7279\u522b\u6709\u7528\u3002\u5b83\u4eec\u4e0d\u4ec5\u63d0\u9ad8\u4e86\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\uff0c\u800c\u4e14\u4f7f\u7528\u8df3\u8f6c\u8868(jump table)\u8fd9\u4e2a\u6570\u636e\u7ed3\u6784\u4f7f\u7528\u5b9e\u73b0\u66f4\u52a0\u9ad8\u6548\u3002\u8df3\u8f6c\u8868\u662f\u4e00\u4e2a\u6570\u7ec4\uff0c\u8868\u9879i\u662f\u4e00\u4e2a\u4ee3\u7801\u6bb5\u7684\u5730\u5740\uff0c\u8fd9\u4e2a\u4ee3\u7801\u6bb5\u5b9e\u73b0\u5f53switch\u7d22\u5f15\u503c\u7b49\u4e8ei\u65f6\u7a0b\u5e8f\u5e94\u8be5\u6267\u884c\u7684\u52a8\u4f5c\u3002\u7a0b\u5e8f\u4ee3\u7801\u7528\u4e8e\u7d22\u5f15\u503c\u6765\u6267\u884c\u4e00\u4e2a\u8df3\u8f6c\u8868\u5185\u7684\u6570\u7ec4\u5f15\u7528\uff0c\u786e\u5b9a\u8df3\u8f6c\u6307\u4ee4\u7684\u76ee\u6807\u3002<br \/>\n\u548c\u4f7f\u7528\u4e00\u7ec4\u5f88\u957f\u7684if-else\u76f8\u6bd4\uff0c\u4f7f\u7528\u8df3\u8f6c\u8868\u7684\u4f18\u70b9\u662f\u6267\u884cswitch\u8bed\u53e5\u7684\u65f6\u95f4\u4e0eswitch\u7684case\u6570\u91cf\u65e0\u5173\u3002GCC\u6839\u636eswitch\u8bed\u53e5\u4e2dcase\u7684\u6570\u91cf\u548ccase\u4e2d\u503c\u7684\u7a00\u5c11\u7a0b\u5e8f\u6765\u7ffb\u8bd1\u5f00\u5173\u8bed\u53e5\u3002\u5f53case\u6570\u636e\u6bd4\u8f83\u591a\uff08\u4f8b\u59824\u4e2a\u4ee5\u4e0a\uff09\uff0c\u5e76\u4e14\u503c\u7684\u8303\u56f4\u8de8\u5ea6\u6bd4\u8f83\u5c0f\u65f6\uff0c\u5c31\u4f1a\u4f7f\u7528\u8df3\u8f6c\u8868\u3002\u4ece\u4e2d\u4e5f\u770b\u51fa\u4e86\uff0c\u5f53\u6761\u4ef6\u5f88\u591a\u65f6\uff0c\u5c3d\u91cf\u4f7f\u7528switch\u66ff\u4ee3if else 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