Answer by Vuong for How to check if multiple array keys exists

<?phpfunction check_keys_exists($keys_str = "", $arr = array()){    $return = false;    if($keys_str != "" and !empty($arr)){        $keys = explode(',', $keys_str);        if(!empty($keys)){            foreach($keys as $key){                $return = array_key_exists($key, $arr);                if($return == false){                    break;                }            }        }    }    return $return;}

//run demo

$key = 'a,b,c';$array = array('a'=>'aaaa','b'=>'ccc','c'=>'eeeee');var_dump( check_keys_exists($key, $array));