JavaScript实现省市级联效果实例

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>省市级联效果</title>
<script type="text/javascript">
    function selectCity(){
        var objProvince=document.getElementById("province");
        var objCity=document.getElementById("city");
        //objCity.length=0; //清空下拉列表选项
        objCity.options.length=0;
        switch(objProvince.value){
                case "1":
                    objCity.add(new Option("南京","1"),null);
                    objCity.add(new Option("苏州","2"),null);
                    objCity.add(new Option("无锡","3"),null);
                    objCity.add(new Option("南通","4"),null);
                    break;
                case "2":
                    objCity.add(new Option("济南","1"),null);
                    objCity.add(new Option("青岛","2"),null);
                    objCity.add(new Option("日照","3"),null);
                    objCity.add(new Option("烟台","4"),null);
                    break;
                case "3":
                    objCity.add(new Option("广州","1"),null);
                    objCity.add(new Option("东莞","2"),null);
                    objCity.add(new Option("深圳","3"),null);
                    objCity.add(new Option("佛山","4"),null);
                    break;                  
        }
    }
</script>
</head>
<body>
    <form action="" method="post">
        <select id="province" onchange="selectCity();">
            <option value="0">--省份--</option>
            <option value="1">江苏省</option>  
            <option value="2">山东省</option>              
            <option value="3">广东省</option>              
            <option value="4">浙江省</option>  
            <option value="5">云南省</option>                                  
        </select>
        <select id="city">
            <option value="0">--城市--</option>
        </select>
    </form>
</body>
</html>

数组-省市级联

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>数组-省市级联</title>
<script type="text/javascript">

    //定义省份城市数组
    var provinces=new Array();
    provinces["江苏省"]=["南京市","苏州市","徐州市","宿迁市"];
    provinces["山东省"]=["济南市","日照市","烟台市","青岛市"]; 
    provinces["浙江省"]=["杭州市","宁波市","义务市","温州市"];
    provinces["广东省"]=["广州市","佛山市","东莞市","珠海市"];
    //初始化省份信息
    function init(){
    var objProvince=document.getElementById("province");
    for(var p in provinces){
        objProvince.add(new Option(p,p),null);
        }
    }
    //切换城市
    function changeCity(){
        var objProvince=document.getElementById("province");
        var objCity=document.getElementById("city");
        objCity.length=0;
        //方式一:
/*          for(var p in provinces){
                if(p==objProvince.value){
                    for(var c in provinces[p]){
                        objCity.add(new Option(provinces[p][c],provinces[p][c]),null);
                    }
                }
            }   */  
        //方式二:
            for(var p in provinces[objProvince.value]){
                objCity.add(new Option(provinces[objProvince.value][p],provinces[objCity.value]),null);
            }
    }
            window.onload=init;
</script>
</head>
<body>
    <form action="" method="post">
        <select id="province" onchange="changeCity();">
            <option value="0">--省份--</option>
        </select>
        <select id="city">
            <option value="0">--城市--</option>
        </select>
    </form>
</body>
</html>
原文地址:https://www.cnblogs.com/JOEH60/p/5703862.html