<script>
  window.onload = function() {
    console.log(city)
    var oDiv = document.getElementById("div");
    var sheng = document.createElement("select");
    var shi = document.createElement("select");
    var qu = document.createElement("select");
    oDiv.appendChild(sheng);
    oDiv.appendChild(shi);
    oDiv.appendChild(qu);
    sheng.options[0] = new Option("请选择省","-1");
    shi.options[0] = new Option("请选择市","-1");
    qu.options[0] = new Option("请选择区","-1");
    //创建省市区完毕
    //循环第一步
    for (var i = 0; i < city.length; i++) {
      sheng.options[sheng.length] = new Option(city[i].name,i);
      sheng.onchange = function() {
        //恢复默认选项
        //shi.options[0].selected = true;
        //qu.options[0].selected = true;
        //清空市区选项
        shi.options.length = 0;
        shi.options[shi.length] = new Option("请选择市","-1");
        qu.options.length = 0;
        qu.options[qu.length] = new Option("请选择区","-1");
        for (var j = 0; j < city[sheng.selectedIndex - 1].city.length; j++) {
          shi.options[shi.length] = new Option(city[sheng.selectedIndex - 1].city[j].name,j);
          shi.onchange = function() {
            //恢复默认选项
            //qu.options[0].selected = true;
            //清空区选项
            qu.options.length = 0;
            qu.options[qu.length] = new Option("请选择区","-1");
            for (var k = 0; k < city[sheng.selectedIndex - 1].city[shi.selectedIndex - 1].area.length; k++) {
              qu.options[qu.length] = new Option(city[sheng.selectedIndex - 1].city[shi.selectedIndex - 1].area[k],k);
            }
          }
        }
      }
    }
  }
</script>
<div id='div'></div>