Online PHP editor | refs for reMX8

<?php $muLevelIds = [1,6,7,8,9]; $subjectLevelIds = [1,6,7,8]; $occLevelIds = [6,7]; var_dump(array_union($muLevelIds, $subjectLevelIds, $occLevelIds)); function array_union($muLevelIds, $subjectLevelIds, $occLevelIds) { $allLevelIds = [1,6,7,8,9]; $arrays = [$muLevelIds, $subjectLevelIds, $occLevelIds]; $comp = [$allLevelIds]; foreach ($arrays as $arr) { if (count($arr)) { $comp[] = $arr; } } $combined = call_user_func_array('array_intersect', $comp); return $combined; }