js完整省市区三级级联

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>省市区三级级联</title>
</head>
<body>
    <select id="province">
        <option value="">请选择省份</option>
    </select>
    <select id="city">
        <option value="">请选择城市</option>
    </select>
    <select id="area">
        <option value="">请选择区域</option>
    </select>

    <script>
        const data = {
            "北京市": {
                "北京市": ["东城区", "西城区", "朝阳区"]
            },
            "上海市": {
                "上海市": ["黄浦区", "徐汇区", "长宁区"]
            }
            // 更多省市区数据...
        };

        const provinceSelect = document.getElementById('province');
        const citySelect = document.getElementById('city');
        const areaSelect = document.getElementById('area');

        // 初始化省份选项
        for (let province in data) {
            let option = document.createElement('option');
            option.value = province;
            option.text = province;
            provinceSelect.appendChild(option);
        }

        // 省份选择变化时更新城市选项
        provinceSelect.addEventListener('change', function() {
            let selectedProvince = this.value;
            citySelect.innerHTML = '<option value="">请选择城市</option>';
            areaSelect.innerHTML = '<option value="">请选择区域</option>';
            if (selectedProvince) {
                for (let city in data[selectedProvince]) {
                    let option = document.createElement('option');
                    option.value = city;
                    option.text = city;
                    citySelect.appendChild(option);
                }
            }
        });

        // 城市选择变化时更新区域选项
        citySelect.addEventListener('change', function() {
            let selectedProvince = provinceSelect.value;
            let selectedCity = this.value;
            areaSelect.innerHTML = '<option value="">请选择区域</option>';
            if (selectedCity) {
                data[selectedProvince][selectedCity].forEach(area => {
                    let option = document.createElement('option');
                    option.value = area;
                    option.text = area;
                    areaSelect.appendChild(option);
                });
            }
        });
    </script>
</body>
</html>