js 联动选项

<select id="province">
    <option value="">请选择省份</option>
    <option value="guangdong">广东</option>
    <option value="jiangsu">江苏</option>
</select>

<select id="city">
    <option value="">请选择城市</option>
</select>

<script>
const provinceSelect = document.getElementById('province');
const citySelect = document.getElementById('city');

// 假设的城市数据
const cities = {
    guangdong: ['广州', '深圳', '珠海'],
    jiangsu: ['南京', '苏州', '无锡']
};

provinceSelect.addEventListener('change', function() {
    const province = this.value;
    citySelect.innerHTML = '<option value="">请选择城市</option>'; // 清空城市选项

    if (province && cities[province]) {
        cities[province].forEach(city => {
            const option = document.createElement('option');
            option.value = city;
            option.textContent = city;
            citySelect.appendChild(option);
        });
    }
});
</script>