{"id":35,"date":"2014-07-22T16:21:40","date_gmt":"2014-07-22T08:21:40","guid":{"rendered":"http:\/\/www.phpzl.com\/?p=35"},"modified":"2014-07-22T16:21:40","modified_gmt":"2014-07-22T08:21:40","slug":"php-%e5%b8%b8%e9%87%8f%e5%ae%9a%e4%b9%89-const%e4%b8%8edefine%e7%9a%84%e5%8c%ba%e5%88%ab","status":"publish","type":"post","link":"http:\/\/www.phpzl.com\/?p=35","title":{"rendered":"php \u5e38\u91cf\u5b9a\u4e49 const\u4e0edefine\u7684\u533a\u522b"},"content":{"rendered":"<p>\u5728php\u4e2d\u5b9a\u4e49\u5e38\u91cf\u65f6\uff0c\u53ef\u7528\u5230const\u4e0edefine\u8fd9\u4e24\u79cd\u65b9\u6cd5\uff0c\u90a3\u4ed6\u4eec\u5230\u5e95\u6709\u4ec0\u4e48\u533a\u522b\u5462\uff1f<\/p>\n<p>1.const\u7528\u4e8e\u7c7b\u6210\u5458\u53d8\u91cf\u7684\u5b9a\u4e49\uff0c\u4e00\u7ecf\u5b9a\u4e49\uff0c\u4e0d\u53ef\u4fee\u6539\u3002define\u4e0d\u53ef\u7528\u4e8e\u7c7b\u6210\u5458\u53d8\u91cf\u7684\u5b9a\u4e49\uff0c\u53ef\u7528\u4e8e\u5168\u5c40\u5e38\u91cf\u3002<\/p>\n<p>2.const\u53ef\u5728\u7c7b\u4e2d\u4f7f\u7528\uff0cdefine\u4e0d\u80fd\u3002<\/p>\n<p>3.const\u4e0d\u80fd\u5728\u6761\u4ef6\u8bed\u53e5\u4e2d\u5b9a\u4e49\u5e38\u91cf\u3002<\/p>\n<p>\u5982\uff1aif(constition){<\/p>\n<p>\u54f2\u7406\u4e0d\u80fd\u7528const\uff0c\u53ea\u80fd\u7528define<\/p>\n<p>}<\/p>\n<p>4.const\u53ea\u80fd\u63a5\u53d7\u9759\u6001\u7684\u6807\u91cf\uff0c\u800cdefine\u53ef\u91c7\u7528\u4efb\u4f55\u7684\u8868\u8fbe\u5f0f\u3002<\/p>\n<p>const BIT_5 = 1 &lt;&lt; 5;\u00a0\u00a0\u00a0 \/\/ invalid<br \/>\ndefine(&#8216;BIT_5&#8217;, 1 &lt;&lt; 5); \/\/ valid<\/p>\n<p>5.const\u5b9a\u4e49\u7684\u5e38\u91cf\u65f6\u5927\u5c0f\u5199\u654f\u611f\u7684\uff0c\u800cdefine\u53ef\u901a\u8fc7\u7b2c\u4e09\u4e2a\u53c2\u6570\uff08\u4e3atrue\u8868\u793a\u5927\u5c0f\u5199\u4e0d\u654f\u611f\uff09\u6765\u6307\u5b9a\u5927\u5c0f\u5199\u662f\u5426\u654f\u611f\u3002<\/p>\n<p>6.const\u91c7\u7528\u4e00\u4e2a\u666e\u901a\u7684\u5e38\u91cf\u540d\u79f0\u3002\u800cdefine\u53ef\u91c7\u7528\u8868\u8fbe\u5f0f\u4f5c\u4e3a\u5e38\u91cf\u3002<\/p>\n<p>7.\u4f7f\u7528const\u4f7f\u5f97\u4ee3\u7801\u7b80\u5355\u6613\u8bfb\uff0cconst\u672c\u8eab\u5c31\u662f\u4e00\u4e2a\u8bed\u8a00\u7ed3\u6784\u3002\u800cdefine\u662f\u4e00\u4e2a\u51fd\u6570\u3002<\/p>\n<p>8.const\u5728\u7f16\u8bd1\u65f6\u6bd4define\u5feb\u5f88\u591a\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p class=\"qua-blog-post-description\">\u5728php\u4e2d\u5b9a\u4e49\u5e38\u91cf\u65f6\uff0c\u53ef\u7528\u5230const\u4e0edefine\u8fd9\u4e24\u79cd\u65b9\u6cd5\uff0c\u90a3\u4ed6\u4eec\u5230\u5e95\u6709\u4ec0\u4e48\u533a\u522b\u5462\uff1f 1.const\u7528\u4e8e\u7c7b [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13,14],"tags":[],"_links":{"self":[{"href":"http:\/\/www.phpzl.com\/index.php?rest_route=\/wp\/v2\/posts\/35"}],"collection":[{"href":"http:\/\/www.phpzl.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.phpzl.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.phpzl.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"http:\/\/www.phpzl.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=35"}],"version-history":[{"count":0,"href":"http:\/\/www.phpzl.com\/index.php?rest_route=\/wp\/v2\/posts\/35\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.phpzl.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=35"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.phpzl.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=35"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.phpzl.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=35"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}