php基础-define跟defined函数的使用
php基础-define和defined函数的使用
??? define("TEST_ATTR","hhhhhhh");
??? echo TEST_ATTR;
?
define相当于java中的constant用来定义一个常量；
?
defined() 函数检查某常量是否存在。
若常量存在，则返回 true，否则返回 false。
?
define("GREETING","Hello world!");echo <code>defined("GREETING")</code>;
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