Online PHP editor | refs for b35Gf

<?php function getTree($treeByParent, $treeByCat, $id, $lastId) { $gTree = []; if ($id != $lastId) { $gTree[] = $id; if ( isset($treeByCat[ $id ]) && count($treeByCat[ $id ]) > 0 ) $gTree = array_merge( getTree($treeByParent, $treeByCat, $treeByCat[ $id ], $id), $gTree); if ( isset($treeByParent[ $id ]) && count($treeByParent[ $id ]) > 0 ) { foreach ($treeByParent[ $id ] as $cat) $gTree = array_merge( getTree($treeByParent, $treeByCat, $cat, $id), $gTree); } return $gTree; } } $treeByParent = array( 0 => array(1, 2), 1 => array(3, 7), 3 => array(4), 4 => array(5), 5 => array(6, 8) ); $treeByCat = array( 1 => 0, 2 => 0, 3 => 1, 7 => 1, 4 => 3, 5 => 4, 6 => 5, 8 => 5 ); print_r( getTree($treeByParent, $treeByCat, 4) );