3v4l.org

run code in 500+ PHP versions simultaneously
<?php $liste = [[1,2,3],5,[['x','y','z'],true]]; array_walk_recursive($liste, function($v) use (&$flat){ $flat[] = $v; }); var_export($flat);
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 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 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
array ( 0 => 1, 1 => 2, 2 => 3, 3 => 5, 4 => 'x', 5 => 'y', 6 => 'z', 7 => true, )
preferences:
115.46 ms | 1952 KiB | 4 Q