__CLASS__与get_class()

__CLASS__ 返回的是调用它的函数所在的类名，而 get_class($this) 返回的是创建对象的类
?php
class test {
   function whoami() {
     echo "Hello, I'm whoami 1 !
";
     echo "Value of __CLASS__ : ".__CLASS__."
";
     echo "Value of get_class() : ".get_class($this)."
";
   }
}
class test2 extends test {
   function whoami2() {
     echo "Hello, I'm whoami 2 !
";
     echo "Value of __CLASS__ : ".__CLASS__."
";
     echo "Value of get_class() : ".get_class($this)."
";
     parent::whoami(); // call parent whoami() function
   }
}
$test=new test;
$test->whoami();
$test2=new test2;
$test2->whoami();
$test2->whoami2();
?>
输出：
Hello, I'm whoami 1 !
Value of __CLASS__ : test
Value of get_class() : test
Hello, I'm whoami 1 !
Value of __CLASS__ : test
Value of get_class() : test2
Hello, I'm whoami 2 !
Value of __CLASS__ : test2
Value of get_class() : test2
Hello, I'm whoami 1 !
Value of __CLASS__ : test
Value of get_class() : test2