public static function is_real_user($userid, $checkdb = false) {
        global $DB;

        if ($userid <= 0) {
            return false;
        }
        if ($checkdb) {
            return $DB->record_exists('user', array('id' => $userid));
        } else {
            return true;
        }
    }
public static function is_real_user($userid, $checkdb = false) {
        global $DB;

        if ($userid <= 0) {
            return false;
        }
        if ($checkdb) {
            return $DB->record_exists('user', array('id' => $userid));
        } else {
            return true;
        }
    }
public static function is_real_user ( $ userid , $ checkdb = false ) { global $ DB ; if ( $ userid <= 0 ) { return false ; } if ( $ checkdb ) { return $ DB -> record_exists ( 'user' , array ( 'id' => $ userid ) ) ; } else { return true ; } }
Return true if user id is greater than 0 and alternatively check db.

@param int $userid user id.
@param bool $checkdb if true userid will be checked in db. By default it's false, and
userid is compared with 0 for performance.
@return bool true is real user else false.
Return true if user id is greater than 0 and alternatively check db .