jquery 联动下拉菜单

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>jQuery 联动下拉菜单</title>
    <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
</head>
<body>
    <select id="country">
        <option value="">请选择国家</option>
        <option value="china">中国</option>
        <option value="usa">美国</option>
    </select>
    <select id="city">
        <option value="">请选择城市</option>
    </select>

    <script>
        $(document).ready(function() {
            $('#country').change(function() {
                var country = $(this).val();
                var cities = {
                    'china': ['北京', '上海', '广州'],
                    'usa': ['纽约', '洛杉矶', '芝加哥']
                };

                var citySelect = $('#city');
                citySelect.empty();
                citySelect.append('<option value="">请选择城市</option>');

                $.each(cities[country], function(index, city) {
                    citySelect.append('<option value="' + city + '">' + city + '</option>');
                });
            });
        });
    </script>
</body>
</html>