How to access constant defined in child class from parent class functions?

Question

I saw this example from php.net:

Answer 1

I couldn't get it to work with const as it prints "yonderyonder" (that's the thing about constants, they don't change), but it works fine with var:

MY_CONST;
     }
}

class ChildClass extends MyClass {

     var $MY_CONST = "bar";
}

$x = new ChildClass(); // prints 'bar'
$y = new MyClass(); // prints 'yonder'

?>