3v4l.org

run code in 300+ PHP versions simultaneously
<?php function abc(?string $abc) { var_dump($abc); } abc(null);
Output for 7.1.0 - 7.1.33, 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
NULL
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33
Parse error: syntax error, unexpected '?', expecting variable (T_VARIABLE) in /in/VEciT on line 3
Process exited with code 255.
preferences:
230.96 ms | 402 KiB | 292 Q