Php проблема с подсчётом элементов в массиве

<?php
$pass = filter_var(trim($_POST['password']), FILTER_SANITIZE_STRING);
$login = filter_var(trim($_POST['login']), FILTER_SANITIZE_STRING);

$link = mysqli_connect("localhost", "root", "", "portal");
$result = $link->query("SELECT * FROM `persons` WHERE `login` = '$login' AND `password` = '$pass'");
$user = $result->fetch_assoc();
try {
$temp = count($user);
} catch (Exception $e) {
$temp = 0;
}

if ($temp == 0 ) {
echo "Пользователя не существует";
exit();
}

setcookie('user', $user['username'], time() + 3600 * 24 * 30, "/");

$link->close();

?>