Messing Around With PHP’s Late Static Binding

Sep 29th, 2014 2:39 pm | Comments

Some weird PHP behavior I stumbled over while debugging our software. This is known at least since 2009 (https://bugs.php.net/bug.php?id=50031). Maybe this opens a few new possibilities for dependency injection or nasty hacks.

<?php /** * @link https://l-x.github.io/blog/2014/09/29/messing-around-with-phps-late-static-binding/ */ class A { public function createInstance() { /** * Calling method static even if * defined non-static in class B */ return B::createInstance(); } } class B { public function createInstance() { return new static(); } } $instance_of_A = new A(); $expected_instance_of_B = $instance_of_A->createInstance(); var_dump($expected_instance_of_B); /** * Expected: * * class B#2 (0) { * * } * * Result: * * class A#2 (0) { * * } * */