3v4l.org

run code in 500+ PHP versions simultaneously
<?php var_dump(isset($a)); $a = null; var_dump(isset($a));
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 - 8.1.34, 8.2.0 - 8.2.32, 8.3.0 - 8.3.33, 8.4.1 - 8.4.24, 8.5.0 - 8.5.9
bool(false) bool(false)
preferences:
52.55 ms | 1649 KiB | 4 Q