Online PHP editor | output for eNu0U

<?php $array = [ 1 => [ [ ['catName' => 'Villes', 'catUrl' => 'villes', 'parent' => 151], [ ['catName' => 'Administratif', 'catUrl' => 'territoire', 'parent' => 37], [ ['catName' => 'Gegraphie', 'catUrl' => 'geographie', 'parent' => 0] ] ] ] ] ]; function flattenRows($array) { $result = []; $scalars = array_filter($array, 'is_scalar'); if ($scalars) { $result[] = $scalars; } foreach (array_diff_key($array, $scalars) as $item) { $result = array_merge($result, flattenRows($item)); } return $result; } $result = []; foreach ($array as &$parent) { $parent = flattenRows($parent); } var_export($array);