Online PHP editor | output for svV96

<?php interface KeyInterface { public function open(); } class MagnetKey implements KeyInterface { public function open() { print 'open by magnet key:'; $this->slide(); } private function slide() { print 'slide down.'; } } class TurnKey implements KeyInterface { public function open() { print 'open by turn key:'; $this->insert(); $this->turn(); } private function insert() { print 'insert key.'; } private function turn() { print 'turn key.'; } } class Key { public function open() { print 'open door:'; $this->insert(); $this->turn(); } private function insert() { print 'insert key.'; } private function turn() { print 'turn key.'; } } class MagnetKeOld extends Key { public function open() { print 'open by magnet key:'; $this->insert(); $this->slide(); } private function slide() { print 'slide key.'; } } $k = new TurnKey(); $k->open(); $mk = new MagnetKey(); $mk->open(); interface Testable { public function test(); } interface MyCountable { public function count(); } abstract class MyAbstract { public abstract function test(); } class MyClass implements Testable, MyCountable { public function test() { print 'this is test method'; } public function count() { print 'this is count method'; } } $o = new MyClass(); $o->test(); $o->count();