Online PHP editor | refs for BrDGu

<?php $array = [ 'id_1_1' => 'id1', 'foo_1_2' => 'value1_1', 'bar_1_3' => 'value1_2', 'more_1_4' => 'value1_3', 'id_2_1' => 'id2', 'foo_2_2' => 'value2_1', 'bar_2_3' => 'value2_2', 'more_2_4' => 'value2_3' ]; function convert($a) { $map = [ ]; $result = []; foreach ($a as $array_key => $value) { list($newkey, $number) = explode('_', $array_key); if ($newkey === 'id') { $map[$number] = $value; $result[$value] = []; } elseif (key_exists($number, $map)) { $id = $map[$number]; $result[$id][$newkey] = $value; } } return $result; } $result = convert($array); var_export($result);