What does “%sUser” and “%d” mean in this code?

[Rei]

PHP function:\[code\]public static function getById($uid){ $u = new User(); $query = sprintf('SELECT USERNAME, PASSWORD, EMAIL_ADDR, IS_ACTIVE ' . 'FROM %sUSER WHERE USER_ID = %d', DB_TBL_PREFIX, $uid); $result = mysql_query($query, $GLOBALS['DB']); if (mysql_num_rows($result)) { $row = mysql_fetch_assoc($result); $u->username = $row['USERNAME']; $u->password = $row['PASSWORD']; $u->emailAddr = $row['EMAIL_ADDR']; $u->isActive = $row['IS_ACTIVE']; $u->uid = $uid; } mysql_free_result($result); return $u;}\[/code\]Pls help me i can't understand what did mean by this "%sUser" and "%d"