Online PHP editor | refs for RWKX0

<?php $i = 0; function is_cyclic(array &$array) { global $i; // Exit when too deep. if (++$i > 10) exit; echo "Call $i:\n"; var_dump($array); echo "\n"; $lastKey = array_key_last($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($item)) { //array_pop($array); return true; } } //array_pop($array); return false; } function craft_bomb() { $array = [1, [2, 3]]; $array[1][1] = &$array; return $array; } $bomb = craft_bomb(); is_cyclic($bomb);