Why is the array not displayed?

Question

PHP

The array is not displayed using the command print_r($user); . Just to see what happened.

$login = filter_var(trim($_POST['login']),
    FILTER_SANITIZE_STRING);
    $pass = filter_var(trim($_POST['pass']),
    FILTER_SANITIZE_STRING);

    $pass = md5($pass."adadagff231313");

    $mysql = new mysqli('localhost', 'root', 'root', 'register-bd');
    
    $result = $mysql->query("SELECT * FROM `users` WHERE `login` = '$login' AND `pass` = '$pass'");
    $user = $result->fetch_assoc();
    if(count($user) == 0) {
        echo "Такой пользователь не найден";
        exit();
    }

    print_r($user);
    exit();

    $mysql->close();

    header('Location: /');