Online PHP editor | refs for mR3oG

<?php $items = array( (object) array('id' => 1, 'parent_id' => 0), (object) array('id' => 2, 'parent_id' => 1), (object) array('id' => 3, 'parent_id' => 1), (object) array('id' => 4, 'parent_id' => 2), (object) array('id' => 5, 'parent_id' => 4), (object) array('id' => 6, 'parent_id' => 0), ); function buildTree($items) { $childs = array(); foreach($items as $item) $childs[$item->parent_id][] = $item; foreach($items as $item) if (isset($childs[$item->id])) $item->childs = $childs[$item->id]; return $childs[0]; } $tree = buildTree($items); print_r($tree);