3v4l.org

run code in 300+ PHP versions simultaneously
<?php function f($a) { if ($a > 0) { $b = f($a-1); } return $b; } echo f(1);
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.29, 8.2.0 - 8.2.21, 8.3.0 - 8.3.9
Warning: Undefined variable $b in /in/4m0HZ on line 6
Output for 5.5.0 - 5.5.35, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.25, 7.4.27 - 7.4.33
Notice: Undefined variable: b in /in/4m0HZ on line 6
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 7.3.32 - 7.3.33, 7.4.26
preferences:
259.9 ms | 405 KiB | 365 Q