3v4l.org

run code in 300+ PHP versions simultaneously
<?php class Foo {} class Bar extends Foo {} class A { public function foo(): Foo {} } class B extends A { public function foo(): Bar {} }
Output for 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.30, 8.2.0 - 8.2.24, 8.3.0 - 8.3.12
Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33
Fatal error: Declaration of B::foo(): Bar must be compatible with A::foo(): Foo in /in/YaolE on line 12
Process exited with code 255.
preferences:
84.59 ms | 407 KiB | 5 Q