對於靜態繫結中的static::在此不多做解釋,我想用例項來證明,這個例子是來自官方文件：

For example one：

class A{
   private function foo(){
       echo "this is a test function"."<br>";
   }

   public function test(){
       $this->foo();
       static::foo();
   }
}

$A=new A();
$A->test();

輸出結果：
this is a test function
this is a test function

For example Two:

class A{
   private function foo(){
       echo "this is a test function"."<br>";
   }

   public function test(){
       $this->foo();
       static::foo();
   }
}

class B extends A{
}

$B=new B();
$B->test();

輸出結果：
this is a test function
this is a test function

For example three：

class A{
   private function foo(){
       echo "this is a test function"."<br>";
   }

   public function test(){
       $this->foo();
       static::foo();
   }
}

class B extends A{
}

class  C extends A{
   private function foo(){

   }    
} 

$C=new C();
$C
 
->test();

輸出結果：
this is a test function
( ! ) Fatal error: Call to private method C::foo() from context ‘A’ in D:\www\testXdebug\index.php on line 21
Call Stack
Time Memory Function Location
1 0.0156 135536 {main}( ) …\index.php:0
2 0.0156 135936 A->test( ) …\index.php:35

其中還有些問題我沒想通，待下文…

class A{
   public static function foo(){
       echo "this is a test function"."<br>";
   }

   public function test(){
       $this->foo();
       static::foo();
   }
}

class B extends A{
}

class  C extends A{
   public static function foo(){
      echo "asdasd"."<br>";
   }    
} 

$c=new C();
$c->test();

輸出結果：
asdasd
asdasd

class A{
    private function foo(){
        echo "this is a test function"."<br>";
    }

    public function test(){
        $this->foo();
        static::foo();
    }
}

class B extends A{
}

class  C extends A{
    protected  function foo(){
        echo "asdasd"."<br>";
    }
}


$c=new C();
$c->test();

輸出結果：
this is a test function
asdasd