JavaScript 实现省市区三级联动菜单

<!DOCTYPE html>
<html>
<head>
 <meta charset="utf-8">
 <title>省市区三级联动</title>
</head>
<body>
 <form>
 <select id="province">
 <option>请选择省份</option>
 </select>
 <select id="city">
 <option>请选择城市</option>
 </select>
 <select id="district">
 <option>请选择区域</option>
 </select> 
 </form>
 <script src="json.js"></script>
 <script type="text/javascript">
 var proData = [],
 cityData = [],
 distData = [];
 var proSelect = document.getElementById("province"),
 citySelect = document.getElementById("city"),
 districtSelect = document.getElementById("district");
 var curPro = "",
 curCity = "";
 // 封装更新选择列表函数
 function fillselect(select,list){
 for (var i = select.length-1; i > 0 ; i--){
 select.remove(i);
 }
 list.forEach(function(data){
 var option = new Option(data.name, data.sheng);
 option.dataset.di = data.di;
 select.add(option);
 })
 }
 // 将数据按省、市、地区分别存储
 dataJson.forEach(function(data){
 if (data.level === 1){
 proData.push(data);
 }
 if (data.level === 2){
 cityData.push(data);
 }
 if (data.level === 3){
 distData.push(data);
 }
 })
 fillselect(proSelect,proData);
 // 监听一级省份选择列表change事件，更新二级城市列表
 proSelect.addEventListener("change",function(event){
 var val = event.target.value;
 var list = [];
 cityData.forEach(function(d){
 if (d.sheng === val) {
 list.push(d);
 }
 })
 fillselect(citySelect,list);
 })
 // 监听二级城市选择列表change事件，更新三级区域列表
 citySelect.addEventListener("change",function(event){
 var val = event.target.value;
 var curIndex = event.target.selectedIndex;
 curCity = event.target[curIndex].dataset.di;
 console.log(event.target,curCity);
 var list = [];
 distData.forEach(function(d){
 if (d.di === curCity && d.sheng === val) {
 list.push(d);
 }
 })
 fillselect(districtSelect,list);
 })
 </script>
</body>
</html>