elseif ($result->num_rows)

Waarvoor dient de regel "elseif ($result->num_rows)" in onderstaande code?

require_once 'login.php';
$connection =
new mysqli($db_hostname, $db_username, $db_password, $db_database);
if ($connection->connect_error) die($connection->connect_error);

if (isset($_SERVER['PHP_AUTH_USER']) &&
isset($_SERVER['PHP_AUTH_PW']))
{
$un_temp = mysql_entities_fix_string($connection, $_SERVER['PHP_AUTH_USER']);
$pw_temp = mysql_entities_fix_string($connection, $_SERVER['PHP_AUTH_PW']);
$query = "SELECT * FROM users WHERE username='$un_temp'";
$result = $connection->query($query);
if (!$result) die($connection->error);
elseif ($result->num_rows)
{
$row = $result->fetch_array(MYSQLI_NUM);
$result->close();
$salt1 = "qm&h*";
$salt2 = "pg!@";
$token = hash('ripemd128', "$salt1$pw_temp$salt2");
if ($token == $row[3])
........