JS实现二级联动菜单-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_44899153/article/details/93922235

效果图
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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>JS实现二级联动菜单</title>
</head>
<body>
<form name="form1" method="post" action="">
    省份：<select name="province" id="province"></select>
    地区：<select name="city" id="city"></select>
</form>
<script>
    var arr_province = ["请选择省/城市","北京市","上海市","天津市","重庆市","深圳市","广东省"];
    var arr_city = [
        ["请选择城市/地区"],
        ["东城区","西城区","朝阳区","宣武区","昌平区","大兴区","丰台区","海淀区"],
        ['宝山区','长宁区','丰贤区', '虹口区','黄浦区','青浦区','南汇区','徐汇区','卢湾区'],
        ['和平区', '河西区', '南开区', '河北区', '河东区', '红桥区', '塘古区', '开发区'],
        ['俞中区', '南岸区', '江北区', '沙坪坝区', '九龙坡区', '渝北区', '大渡口区', '北碚区'],
        ['福田区', '罗湖区', '盐田区', '宝安区', '龙岗区', '南山区', '深圳周边'],
        ['广州市','惠州市','汕头市','珠海市','佛山市','中山市','东莞市']
    ];
    function my$(id) {
        return document.getElementById(id);
    }
    var pro = my$("province");
    var city = my$("city");
    //1.省区的默认选项
    for(var i = 0 ; i < arr_province.length ;i++){
        var option = document.createElement("option");
        option.innerHTML = arr_province[i];
        pro.appendChild(option);
    }
    //2.城市的默认选项
    var cityOption = document.createElement("option");
    cityOption.innerHTML = arr_city[0][0];
    city.appendChild(cityOption);
    //3.绑定change事件
    pro.onchange = function () {
        //获取到当前被选中的索引值
        console.log(this.selectedIndex);
        var index = this.selectedIndex; //2
        //先清除city里面的option选项
        city.innerHTML = "";
        for(var i = 0; i < arr_city[index].length; i++){
            var o = document.createElement("option");
            o.innerHTML = arr_city[index][i];
            city.appendChild(o);
        }
    }
</script>
</body>
</html>

二级联动(js)