3v4l.org

run code in 300+ PHP versions simultaneously
<?php function foo(?string $bar) { } foo(''); foo(null);
Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.30, 8.2.0 - 8.2.25, 8.3.0 - 8.3.14
preferences:
75.84 ms | 407 KiB | 5 Q