3v4l.org

run code in 300+ PHP versions simultaneously
<?php $ao = new ArrayObject([2, 3, 8, 9]); var_dump(array_walk_recursive($ao, function($item, $key){ echo $key . ' => ' . $item . PHP_EOL; }));
Output for 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 - 8.3.6
bool(true)
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.6 - 7.2.33, 7.3.16 - 7.3.33
0 => 2 1 => 3 2 => 8 3 => 9 bool(true)
preferences:
212.51 ms | 403 KiB | 226 Q