3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php declare(strict_types=1); function concat(string $separator = ' ', string ...$strings): string { return implode($separator, $strings); }
Output for 7.0.0 - 7.2.0
Output for 5.3.19 - 5.6.28
Warning: Unsupported declare 'strict_types' in /in/Ut602 on line 3 Fatal error: Default value for parameters with a class type hint can only be NULL in /in/Ut602 on line 5
Process exited with code 255.