3v4l.org

run code in 300+ PHP versions simultaneously
<?php interface CustomSerializable { public function unserialize(string $serialized): void; } class Foo implements CustomSerializable { public function unserialize($serialized): void { // error since incompatible signature, string expected '' found } }
Output for 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
Output for 7.1.25 - 7.1.28
Fatal error: Declaration of Foo::unserialize($serialized): void must be compatible with CustomSerializable::unserialize(string $serialized): void in /in/GJnH9f on line 7
Process exited with code 255.
preferences:
106.7 ms | 407 KiB | 5 Q