Online PHP editor | refs for Nl7PZ

<?php function is_cyclic(array &$array, int $maxDepth = -1) { if ($maxDepth === 0) { throw new Exception('Maximum nesting level exceeded.'); } $lastKey = array_key_last($array); if ($lastKey === null) { // Array is empty return false; } static $marker; if ($marker === null) { $marker = new stdClass(); } if ($array[$lastKey] === $marker) { return true; } $array[] = $marker; foreach ($array as &$item) { if (is_array($item) && is_cyclic($item, $maxDepth - 1)) { array_pop($array); return true; } } array_pop($array); return false; } function craft_bomb() { $array = [1, [2, 3]]; $array[1][1] = &$array; return $array; } $bomb = craft_bomb(); var_export(is_cyclic($bomb, 10));