3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = array('a', 'b', 'c', 'd', 'e', 'f', 'g'); function nestArray($arr) { if(empty($arr)) { return array(); } return array(array_shift($arr) => nestArray($arr)); } var_dump(nestArray($array));
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, 5.5.0 - 5.5.38, 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 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
array(1) { ["a"]=> array(1) { ["b"]=> array(1) { ["c"]=> array(1) { ["d"]=> array(1) { ["e"]=> array(1) { ["f"]=> array(1) { ["g"]=> array(0) { } } } } } } } }

preferences:
328.33 ms | 406 KiB | 455 Q