3v4l.org

run code in 200+ PHP versions simultaneously
<?php class Producer { public function method(): self { } } class ChildProducer extends Producer { public function method(): self { } }
Output for 7.4.0 - 7.4.1
Output for 7.2.0 - 7.3.13
Fatal error: Declaration of ChildProducer::method(): ChildProducer must be compatible with Producer::method(): Producer in /in/GGdhA on line 14
Process exited with code 255.