PHP中如何形成static::与new static()的静态绑定-php教程

PHP中static::与new static()之前期动态绑定

1、parent、self、$this、__CLASS__

class A {}
class B extends A{
parent::(public|protected)(动态办法|动态变量)  ===> parent永远是A
self::(public|protected)(动态办法|动态变量)  ===> self永远是B
$this->(public|protected)(非动态办法|非动态变量)  ===> $this永远是B的是实例化工具
__CLASS__    ===> 永远是B
} 
class C extends B{
parent::(public|protected)(动态办法|动态变量)  ===> parent永远是B
self::(public|protected)(动态办法|动态变量)  ===> self永远是C
$this->(public|protected)(非动态办法|非动态变量)  ===> $this永远是C的是实例化工具
__CLASS__    ===> 永远是C 
}

2、static::

static要害字能够完成如下性能：

1 挪用类的动态办法 有前期动态绑定成果；

2 挪用类的动态属性 有前期动态绑定成果；

3 挪用类的非动态办法 不前期动态绑定成果；

4 留意：不成以挪用非动态属性；

class A {
    private static function foo() {
        echo "A success!\n";
    }
    public function test() {
         $this->foo();
    }
}
 
class B extends A {
}
 
class C extends A {
    private static function foo() {
    echo "C success!\n";
    }
}
 
$b = new B();
$b->test();//A success!
$c = new C();
$c->test();//A success!

class A {
    private static function foo() {
        echo "A success!\n";
    }
    public function test() {
        static::foo();
    }
}
 
class B extends A {
}
 
class C extends A {
    private static function foo() {
    echo "C success!\n";
    }
}
 
$b = new B();
$b->test();//A success!
$c = new C();
$c->test();//A无奈挪用C里的公有foo办法 
 
 
 
 
//将C的foo改为非private(public|protected)就能够处理
class A {
    private static function foo() {
        echo "A success!\n";
    }
    public function test() {
        static::foo();
    }
}
 
class B extends A {
}
 
class C extends A {
    public static function foo() {
    echo "C success!\n";
    }
}
 
$b = new B();
$b->test();//A success!
$c = new C();
$c->test();//C success!

class A {
 public static function foo() {
     static::who();
 }
 
 public static function who() {
     echo __CLASS__."\n";
 }
}
 
class B extends A {
 public static function test() {
     A::foo();
     parent::foo();
     self::foo();
 }
 
 public static function who() {
     echo __CLASS__."\n";
 }
}
class C extends B {
 public static function who() {
     echo __CLASS__."\n";
 } 
}
 
C::test(); 
A =>A::foo()的后果
C =>parent::foo()能走到A的foo,外面static::who找C::who
C =>self::foo()能走到B的foo,B承继A,走到A的foo,外面static::who找C::who
 
 
 
 
 
class A {
    protected static function foo() {
        static::who();
    }
 
    protected static function who() {
        echo __CLASS__."\n";
    }
}
 
class B extends A {
    public static function test() {
        A::foo();
        parent::foo();
        self::foo();
    }
 
    protected static function who() {
        echo __CLASS__."\n";
    }
}
class C extends B {
    protected static function who() {
        echo __CLASS__."\n";
    } 
}
 
C::test(); //A C C,诠释同上
 
 
 
 
 
class A {
 public static function foo() {
     static::who();
 }
 
 private static function who() {
     echo __CLASS__."\n";
 }
}
 
class B extends A {
 public static function test() {
     A::foo();
     parent::foo();
     // self::foo();  
 }
 
 private static function who() {
     echo __CLASS__."\n";
 }
}
class C extends B {
 private static function who() {
     echo __CLASS__."\n";
 } 
}
 
C::test();
//A =>A::foo()的后果 
//报错 A不成C的公有办法who => parent::foo()能走到A的foo,外面static::who找C::who,C的who只能正在C里挪用，不克不及正在A里挪用
//报错 A不成C的公有办法who => self::foo()能走到B的foo,B承继A,走到A的foo,外面static::who找C::who,C的who只能正在C里挪用，不克不及正在A里挪用

3、new static()

//new self()与new static()的区分，官网例子以下： 
class A {
  public static function get_self() {
    return new self();
  }
 
  public static function get_static() {
    return new static();
  }
}
 
class B extends A {}
 
echo get_class(B::get_self()); // A
echo get_class(B::get_static()); // B
echo get_class(A::get_static()); // A

保举教程：《PHP视频教程》

以上就是PHP中若何构成static::与new static()的动态绑定的具体内容，更多请存眷资源魔其它相干文章！