php中 static 和 self的区别

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  class Boo {  
      protected static $str = "This is class Boo";  
      public static function get_info(){  
 
          echo get_called_class().PHP_EOL;  
          echo self::$str.PHP_EOL;  
          echo static::$str.PHP_EOL;
      }
 
      public function __get($name){
          return $name;
      }
 
  }  
  class Foo extends Boo{  
      protected static $str = "This is class Foo";  
  }  
   Foo::get_info();
 
 
   /*
   result:
    Foo
    This is class Boo
    This is class Foo
    self 不会指向实例化的类，而指向本身所在的类， 调用顺序->在本身类中找->找不到报异常
    static 指向实例化的类，调用顺序是 从实例化类中找-->然后找父类-->找不到报异常
   */

class Boo { protected static $str = "This is class Boo"; public static function get_info(){ echo get_called_class().PHP_EOL; echo self::$str.PHP_EOL; echo static::$str.PHP_EOL; } public function __get($name){ return $name; } } class Foo extends Boo{ protected static $str = "This is class Foo"; } Foo::get_info(); /* result: Foo This is class Boo This is class Foo self 不会指向实例化的类，而指向本身所在的类， 调用顺序->在本身类中找->找不到报异常 static 指向实例化的类，调用顺序是 从实例化类中找-->然后找父类-->找不到报异常 */