JavaScript Cascader Area Data: Adding County to City with Single County

```javascript function useCascaderAreaData() { const { city_list: city, county_list: county, province_list: province } = areaList; const provinceMap = // @@PURE// new Map(); Object.keys(province).forEach((code) => { provinceMap.set(code.slice(0, 2), makeOption(province[code], code, [])); }); const cityMap = // @@PURE// new Map(); Object.keys(city).forEach((code) => { const option = makeOption(city[code], code, []); cityMap.set(code.slice(0, 4), option); const province2 = provinceMap.get(code.slice(0, 2)); if (province2) { province2.children.push(option); } });

// 添加只有一个县的城市代码 const countyCode = '110228'; // 县的代码 const countyOption = makeOption(county[countyCode], countyCode); const cityCode = '110100'; // 城市的代码 const cityOption = cityMap.get(cityCode); if (cityOption) { cityOption.children.push(countyOption); }

Object.keys(county).forEach((code) => { const city2 = cityMap.get(code.slice(0, 4)); if (city2) { city2.children.push(makeOption(county[code], code)); } }); return Array.from(provinceMap.values()); } ```

这样修改后，城市代码为110100的城市将包含一个县的数据，该县的代码为110228。