麻烦老师检查下作业，谢谢！

来源：7-8 编程练习

Jongls

2020-11-24 17:21:26

HTML代码：

<!DOCTYPE html>
<html>
<head>
    <title></title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
    <script type="text/javascript" src="index.js"></script>
</head>
<body onload="province()">
    <form>
        <label>省：</label>
        <select name="pro" id="pro" onchange="getCity()"></select>
        <label>市/区：</label>
        <select name="city" id="city"></select>
    </form>
</body>
</html>

JS代码：

//初始化省列表框条目
function province() {
    var pro=document.getElementById("pro");
    var proArray=["","北京市","天津市","河北省","河南省"];
    insertOpints(pro,proArray);
}
//添加列表框条目
function insertOpints(obj,arrary){
    for(var i in arrary){
        obj.options.add(new Option(arrary[i],i));
    }
}
//根据省列表框value，动态添加市/区列表框条目
function getCity(){
    var pro=document.getElementById("pro");
    var city=document.getElementById("city");
    var cityArray;
    p=parseInt(pro.value);
    if(p==0){
        cityArray=[""];
    }else if(p==1){
        cityArray=["朝阳区","西城区"];
    }else if(p==2){
        cityArray=["西青区","武清区"];
    }else if(p==3){
        cityArray=["石家庄","邯郸市"];
    }else{
        cityArray=["郑州市","开封市"];
    }
    city.options.length=0;
    insertOpints(city,cityArray);
}