<?php class A1 { public function A1($id) { $this->id = $id; } } class B1 extends A1 { } class C1 extends B1 { public function __construct($id) { parent::__construct($id); } function zz($id) { parent::__construct($id); } } $x = new C1(100); echo $x->id . "\n"; $x->zz(1); echo $x->id . "\n";