{"id":75,"date":"2016-05-18T01:51:04","date_gmt":"2016-05-18T01:51:04","guid":{"rendered":"http:\/\/120.27.50.22\/wordpress\/?p=75"},"modified":"2016-05-18T01:51:04","modified_gmt":"2016-05-18T01:51:04","slug":"empty%e5%92%8cisset%e5%87%bd%e6%95%b0%e7%9a%84%e5%8c%ba%e5%88%ab","status":"publish","type":"post","link":"http:\/\/www.homconnect.cn\/?p=75","title":{"rendered":"empty()\u548cisset()\u51fd\u6570\u7684\u533a\u522b"},"content":{"rendered":"

empty<\/span> \u2014 \u68c0\u67e5\u4e00\u4e2a\u53d8\u91cf\u662f\u5426\u4e3a\u7a7a<\/span><\/h3>\n

\u5982\u679c var<\/code> \u662f\u975e\u7a7a\u6216\u975e\u96f6\u7684\u503c\uff0c\u5219 empty()<\/strong><\/span> \u8fd4\u56de FALSE<\/code><\/strong>\u3002\u6362\u53e5\u8bdd\u8bf4\uff0c“”<\/em>\u30010<\/i>\u3001“0”<\/em>\u3001NULL<\/code><\/strong>\u3001FALSE<\/code><\/strong>\u3001array()<\/em>\u3001var $var;<\/em> \u4ee5\u53ca\u6ca1\u6709\u4efb\u4f55\u5c5e\u6027\u7684\u5bf9\u8c61\u90fd\u5c06\u88ab\u8ba4\u4e3a\u662f\u7a7a\u7684\uff0c\u5982\u679c var<\/code> \u4e3a\u7a7a\uff0c\u5219\u8fd4\u56de TRUE<\/code><\/strong>\u3002<\/p>\n

\u9664\u4e86\u5f53\u53d8\u91cf\u6ca1\u6709\u7f6e\u503c\u65f6\u4e0d\u4ea7\u751f\u8b66\u544a\u4e4b\u5916\uff0cempty()<\/strong><\/span> \u662f (boolean) var<\/em> \u7684\u53cd\u4e49\u8bcd\u3002<\/p>\n

empty() \u4e0e isset() \u7684\u4e00\u4e2a\u7b80\u5355\u6bd4\u8f83\u3002<\/p>\n

\n

<?php
\n$var\u00a0= 0;
\n\/\/\u00a0\u7ed3\u679c\u4e3a\u00a0true\uff0c\u56e0\u4e3a\u00a0$var\u00a0\u4e3a\u7a7a
\nif\u00a0(empty($var))\u00a0{
\necho\u00a0‘$var\u00a0is\u00a0either\u00a00\u00a0or\u00a0not\u00a0set\u00a0at\u00a0all’;
\n}<\/p>\n

\/\/\u00a0\u7ed3\u679c\u4e3a\u00a0false\uff0c\u56e0\u4e3a\u00a0$var\u00a0\u5df2\u8bbe\u7f6e
\nif\u00a0(!isset($var))\u00a0{
\necho\u00a0‘$var\u00a0is\u00a0not\u00a0set\u00a0at\u00a0all’;
\n}
\n?><\/p>\n<\/blockquote>\n

\u6ce8\u610f<\/b>:<\/p>\n

\u56e0\u4e3a\u662f\u4e00\u4e2a\u8bed\u8a00\u6784\u9020\u5668\u800c\u4e0d\u662f\u4e00\u4e2a\u51fd\u6570\uff0c\u4e0d\u80fd\u88ab \u53ef\u53d8\u51fd\u6570 \u8c03\u7528\u3002 <\/span><\/p>\n

empty()<\/strong><\/span> \u53ea\u68c0\u6d4b\u53d8\u91cf\uff0c\u68c0\u6d4b\u4efb\u4f55\u975e\u53d8\u91cf\u7684\u4e1c\u897f\u90fd\u5c06\u5bfc\u81f4\u89e3\u6790\u9519\u8bef\u3002\u6362\u53e5\u8bdd\u8bf4\uff0c\u540e\u8fb9\u7684\u8bed\u53e5\u5c06\u4e0d\u4f1a\u8d77\u4f5c\u7528\uff1a empty(addslashes($name))<\/strong>\u3002<\/p>\n

\n

isset<\/span> \u2014 \u68c0\u6d4b\u53d8\u91cf\u662f\u5426\u8bbe\u7f6e<\/span><\/h3>\n

\u68c0\u6d4b\u53d8\u91cf\u662f\u5426\u8bbe\u7f6e\uff0c\u5e76\u4e14\u4e0d\u662f NULL<\/code><\/strong>\u3002<\/p>\n

\u5982\u679c\u5df2\u7ecf\u4f7f\u7528 unset() \u91ca\u653e\u4e86\u4e00\u4e2a\u53d8\u91cf\u4e4b\u540e\uff0c\u5b83\u5c06\u4e0d\u518d\u662f isset()\u3002\u82e5\u4f7f\u7528 isset() \u6d4b\u8bd5\u4e00\u4e2a\u88ab\u8bbe\u7f6e\u6210 NULL \u7684\u53d8\u91cf\uff0c\u5c06\u8fd4\u56de FALSE\u3002\u540c\u65f6\u8981\u6ce8\u610f\u7684\u662f\u4e00\u4e2a NULL \u5b57\u8282\uff08”\\0″\uff09\u5e76\u4e0d\u7b49\u540c\u4e8e PHP \u7684 NULL \u5e38\u6570\u3002<\/p>\n

\u5982\u679c var<\/code> \u5b58\u5728\u5e76\u4e14\u503c\u4e0d\u662f NULL<\/code><\/strong> \u5219\u8fd4\u56de TRUE<\/code><\/strong>\uff0c\u5426\u5219\u8fd4\u56de FALSE<\/code><\/strong>\u3002<\/p>\n

Warning<\/strong><\/p>\n

isset()<\/strong><\/span> \u53ea\u80fd\u7528\u4e8e\u53d8\u91cf\uff0c\u56e0\u4e3a\u4f20\u9012\u4efb\u4f55\u5176\u5b83\u53c2\u6570\u90fd\u5c06\u9020\u6210\u89e3\u6790\u9519\u8bef\u3002\u82e5\u60f3\u68c0\u6d4b\u5e38\u91cf\u662f\u5426\u5df2\u8bbe\u7f6e\uff0c\u53ef\u4f7f\u7528 defined()<\/span> \u51fd\u6570\u3002<\/p>\n

\u6ce8\u610f\uff1a<\/strong><\/p>\n

\u56e0\u4e3a\u662f\u4e00\u4e2a\u8bed\u8a00\u6784\u9020\u5668\u800c\u4e0d\u662f\u4e00\u4e2a\u51fd\u6570\uff0c\u4e0d\u80fd\u88ab \u53ef\u53d8\u51fd\u6570 \u8c03\u7528\u3002 <\/span><\/p>\n

\u5982\u679c\u4f7f\u7528 isset()<\/strong><\/span> \u6765\u68c0\u67e5\u5bf9\u8c61\u65e0\u6cd5\u8bbf\u95ee\u7684\u5c5e\u6027\uff0c\u5982\u679c __isset() \u65b9\u6cd5\u5df2\u7ecf\u5b9a\u4e49\u5219\u4f1a\u8c03\u7528\u8fd9\u4e2a\u91cd\u8f7d\u65b9\u6cd5\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

empty \u2014 \u68c0\u67e5\u4e00\u4e2a\u53d8\u91cf\u662f\u5426\u4e3a\u7a7a \u5982\u679c var \u662f\u975e\u7a7a\u6216\u975e\u96f6\u7684\u503c\uff0c\u5219 empty() \u8fd4\u56de FALSE\u3002\u6362 … \u7ee7\u7eed\u9605\u8bfb\u201cempty()\u548cisset()\u51fd\u6570\u7684\u533a\u522b\u201d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[38,39],"_links":{"self":[{"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/posts\/75"}],"collection":[{"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=75"}],"version-history":[{"count":1,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/posts\/75\/revisions"}],"predecessor-version":[{"id":76,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/posts\/75\/revisions\/76"}],"wp:attachment":[{"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=75"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=75"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=75"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}