Online PHP editor | output for vrYV2

<?php abstract class Abst { public function compare(self $object); } interface I { public function compare(self $object); } class A extends Abst { public function compare(self $aObject) { return true; } } class B implements I { public function compare(self $bObject) { return true; } } class C extends A { public function compare(self $bObject) { return true; } } $a = new A(); $b = new B(); $c = new C(); $a->compare($a); $a->compare($b); $a->compare($c);