Online PHP editor | refs for QoFkr

<?php class User { public $address; } class Address { public $street; } $address = new Address(); $address->street = 'Street'; $user = new User(); $user->address = $address; $user2 = new User(); echo $user->address->street ?? ''; echo $user2->address->street ?? ''; var_dump(isset($user->address->street->number->etc));