A.php

<?php
class A {
	public function myage() {
	return  ' age is 80';
	}
}
class B extends A {	
	public function mysonage() {
	return  ' age is 50';
	}
}
class C extends B {
	public function mygrandsonage() {
	return  'age is 20';
	   }
        public function myHistory() {
        echo "Class A " .$this->myage();
        echo "Class B ".$this-> mysonage();
        echo "Class C " . $this->mygrandsonage();
        }
}
$obj = new C();
$obj->myHistory();
?>