3v4l.org

run code in 300+ PHP versions simultaneously
<?php class Foo extends DateTime { const ATOM = 'Y-m-d'; } echo (new DateTime('2015-02-01'))->format(DateTime::ATOM), PHP_EOL; echo (new Foo('2015-02-01'))->format(Foo::ATOM);
Output for 8.5.0 - 8.5.3
Fatal error: Type of Foo::ATOM must be compatible with DateTimeInterface::ATOM of type string in /in/iZEks on line 3 Stack trace: #0 {main}
Process exited with code 255.
Output for 8.4.1 - 8.4.18
Fatal error: Type of Foo::ATOM must be compatible with DateTimeInterface::ATOM of type string in /in/iZEks on line 3
Process exited with code 255.
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33, 8.0.0 - 8.0.12, 8.0.14 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30
2015-02-01T00:00:00+01:00 2015-02-01
Output for 7.3.32 - 7.3.33, 8.0.13
2015-02-01T00:00:00+00:00 2015-02-01
preferences:
114.73 ms | 2098 KiB | 4 Q