Web Front-endJS TutorialImplementing nationwide provincial and municipal second-level linkage drop-down selection menus based on javascript_javascript skills
This article describes the example of js realizing the second-level linkage drop-down selection menu of provinces and cities across the country, and shares it with everyone for your reference. The details are as follows:
Rendering:
Specific code:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<script type="text/javascript">
//好像不是这样子
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","河南省"];
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'],
['郑州市']
];
//函数：当省份中的option改变时，城市中的数据应该相应的改变
function select_change(index)
{
var city = document.form1.city;
//根据当前index确定city中要写入的二维数组是哪一个
city.length = 0;
city.length = arr_city[index].length;
for(var i=0;i<arr_city[index].length;i++)
{
//创建每一个option对象(option标记)
city.options[i].text = arr_city[index][i];
city.options[i].value = arr_city[index][i];
}
}
//函数：给province对象添加option对象，每个option的内容来自于arr_province
function init()
{
//获取province和city对象
var province = document.form1.province;
var city = document.form1.city;
//指定下拉列表的高度，准备写入几个option的标记(很重要)
province.length = arr_province.length; //这句必须有
//循环数组，将数组内容写入到province中去
for(var i=0;i<arr_province.length;i++)
{
//创建每一个option对象(option标记)
province.options[i].text = arr_province[i];
province.options[i].value = arr_province[i];
}
//指定省份当前的默认选中索引号
var index = 0;
province.selectedIndex = index;
//对象city的内容来自于province的选择
//我们默认指定一个option，一般是下标为0的那个
city.length = arr_city[index].length;
for(var j=0;j<arr_city[index].length;j++)
{
//创建每一个option对象(option标记)
city.options[j].text = arr_city[index][j];
city.options[j].value = arr_city[index][j];
}
}
</script>
</head>
<body onload="init()">
<form name="form1">
省份：<select name="province" onchange="select_change(this.selectedIndex)" style="width:130px;"></select>
城市：<select name="city"></select>
</form>
</body>
</html>
I hope this article will be helpful to everyone’s JavaScript programming design.
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