7-8编程练习

来源：7-8 编程练习

流下了没有技术的眼泪

2020-03-22 23:07:55

<html>
<head>
    <meta charset="UTF-8">
<title>Document</title>
    <script type="text/javascript">
    var arr=["北京市","天津市","河北省","河南省"];
    var arr1=["朝阳区","西城区"];
    var arr2=["西青区","武清区"];
    var arr3=["石家庄市","邯郸市"];
    var arr4=["郑州市","开封市"];
 function address(){
     var province=document.getElementById("province");
     var city=document.getElementById("city");
     Selectadd(province,arr);
     Selectadd(city,arr1);
     Selectadd(city,arr2);
     Selectadd(city,arr3);
     Selectadd(city,arr4);
 }   
 function Selectadd(obj,arr){
     for(var i in arr ){
         obj.options.add(new Option(arr[i],arr[i]));
     }
 }
 function linkage(){
     var province=document.getElementById("province");
     var city=document.getElementById("city");
     var pro=province.Value;
     var finalarr=[];
     if(pro==arr[0]){
         finalarr=arr1;

     }else if(pro==arr[1]){
         finalarr=arr2;
        }else if(pro==arr[2]){
        finalarr=arr3;
    }else if(pro==arr[3]){
        finalarr=arr4;
    }
    city.options.length=0;
    selectAdd(city,finalarr);
 }
    
    
    </script>
</head>
<body onload="address()">
<form>
 省份：
<!--  请在此补充代码 -->
<select id="province" onchange="linkage()"></select>
 市/区：
 <!--  请在此补充代码 -->
 <select id="city" ></select>
</form>
</body>
</html>

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