<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
<script src="scripts/jquery-1.7.1.js"></script>
<script>
//$.each(obj,fun(i,n))
//如果obj是数组，则i是索引，n是元素
//如果obj是对象或键值对，i是键，n是值
//定义省市数据，键值对集合
var datas = {
"北京": ["朝阳", "海淀", "昌平", "丰台"],
"山东": ["青岛", "济南", "烟台"],
"山西": ["大同", "太原", "运城", "长治"],
"河南": ["洛阳", "开封", "郑州", "驻马店"],
"河北": ["石家庄", "张家口", "保定"]
};
$(function () {
//创建省的select
var select = $('<select id="selectProvince"></select>');
//追加到body中
select.appendTo('body');
//遍历集合
$.each(datas, function (key, value) {
$('<option>' + key + '</option>').appendTo(select);
});
//创建市的select
var selectCity = $('<select id="selectCity"></select>');
selectCity.appendTo('body');
//获取选中的省信息
var pro = $('#selectProvince').val();
//将省名称作为键到集合中获取值
var citys = datas[pro];
//遍历市的数组
$.each(citys, function (index,item) {
$('<option>' + item + '</option>').appendTo(selectCity);
})
//最后写change事件：为省的select绑定change事件
select.change(function () {
var citys = datas[$(this).val()];
//删除市的原有option
selectCity.empty();
$.each(citys, function (index, item) {
$('<option>' + item + '</option>').appendTo(selectCity);
})
})
})
</script>
</head>
<body>
</body>
</html>