php常量输出

 <?phpdefine("C1", "Hello world./n");//定义C1为常量echo C1;//输出C1echo c1;//变量C1拼写错误，这时不会输出C1的值define("C2", "Hello world./n", TRUE);//设置case_insensitive为TRUEecho C2;//输出C2echo c2;//将C小写输出?>