Online PHP editor | refs for vnUtc

<?php $teacherActiveGroupNameData = [ "100" => ["name" => "1 A"], "200" => ["name" => "1 B"], "300" => ["name" => "1 C"], "400" => ["name" => "1 D"], ]; $activeGroups = [ "user1" => ["100" , "200"], "user2" => ["100" , "300"], "user3" => ["100" , "200","400"], ]; $r = []; foreach($activeGroups as $k => $v){ foreach($v as $ik => $iv){ $r[$k][] = $teacherActiveGroupNameData[$iv]['name']; } } echo '<pre>'; print_r($r);