3v4l.org

run code in 300+ PHP versions simultaneously
<?php declare(strict_types=1); function x(?string $x) { } x(null);
Output for 7.1.0 - 7.1.25, 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 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.7
Output for 7.0.0 - 7.0.20
Parse error: syntax error, unexpected '?', expecting variable (T_VARIABLE) in /in/TKjvD on line 4
Process exited with code 255.
preferences:
143.09 ms | 401 KiB | 189 Q