3v4l.org

run code in 300+ PHP versions simultaneously
<?php class A { public function foo($foo): mixed {} } class B extends A { public function foo($foo) {} }
Output for 8.1.0 - 8.1.30, 8.2.0 - 8.2.25, 8.3.0 - 8.3.13
Fatal error: Declaration of B::foo($foo) must be compatible with A::foo($foo): mixed in /in/BH4qV on line 8
Process exited with code 255.
preferences:
183.17 ms | 1008 KiB | 7 Q