是否有一个关键字引用PHP中祖父类的成员？

Question

class Grandfather {

    protected function stuff() {
        // Code.
    } 
}

class Dad extends Grandfather {
    function __construct() {
        // I can refer to a member in the parent class easily.
        parent::stuff();
    }
}

class Kid extends Dad {
        // How do I refer to the stuff() method which is inside the Grandfather class from here?
}

How can I refer to a member of the Grandfather class from within the Kid class?

My first thought was Classname::method() but is there a keyword available such as self or parent ?

Answer 1

$this->stuff() or Grandfather::stuff()

calling with this will call ::stuff() method on the top of inherit level (in your example it'd be Dad::stuff() , but you don't override ::stuff in Dad class so it'd be Grandfather::stuff() )

and Class::method() will call exact class method

Example code:

    <?php
class Grandfather {

    protected function stuff() {
        echo "Yeeeh";
        // Code.
    } 
}

class Dad extends Grandfather {
    function __construct() {
        // I can refer to a member in the parent class easily.
        parent::stuff();
    }
}

class Kid extends Dad {
    public function doThatStuff(){
        Grandfather::stuff();
    }
      // How do I refer to the stuff() method which is inside the Grandfather class from here?
}
$Kid = new Kid();
$Kid->doThatStuff();

The "Yeeeh" will be outputted 2 times. Because constructor of Dad (which is not overrided in Kid class) class calls Grandfather::stuff() and Kid::doThatStuff() calls it too

Answer 2

1. If stuff() is nowhere overriden in the class hierarchy you can call the function with $this->stuff()
2. If stuff() were to be overriden in Dad you have to call the function with the classname, eg Grandfather::stuff()
3. If stuff() is overriden in Kid , you can do the call via parent::stuff()

Answer 3

If you want call Grandfather::stuff method you can do this using Grandfather::stuff() in Kid class.

Look at this example .