Online PHP editor | output for gMZUR

<?php $arr = [ ['96','90','91'], ['96','90','91'], ['96','90','91','98'], ['96','90','91','98'], ]; $set = []; foreach ($arr as $values) { foreach($values as $each_value){ if(!isset($set[$each_value])) $set[$each_value] = true; } } $result = []; $set = array_keys($set); foreach ($arr as $values) { foreach($set as $value){ if(!in_array($value,$values)) $result[] = $value; } } $result = array_unique($result); print_r($result);