$user_id = 1234;
$metas = array(
'nickname' => $userFirstName,
'first_name' => $userFirstName,
'last_name' => $userLastName ,
'city' => $userCityID ,
'gender' => $userGenderID
);
foreach($metas as $key => $value) {
update_user_meta( $user_id, $key, $value );
}