1，两个下拉框的二级联动
代码：
<!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" οnchange="changeSelect(this.selectedIndex)"></select><br/>地区：<select name="city" id="city"></select></form></body></html><script type="text/javascript">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']];//网页加载完成，初始化菜单window.onload = init;//传入函数地址function init(){//首先获取对象var province = document.form1.province;var city = document.form1.city;//指定省份中<option>标记的个数province.length = arr_province.length;//循环将数组中的数据写入<option>标记中for(var i=0;i<arr_province.length;i++){province.options[i].text = arr_province[i];province.options[i].value = arr_province[i];}//修改省份列表的默认选择项var index = 0;province.selectedIndex = index;//指定城市中<option>标记的个数city.length = arr_city[index].length;//循环将数组中的数据写入<option>标记中for (var j = 0; j<arr_city[index].length;j++) {city.options[j].text = arr_city[index][j];city.options[j].value = arr_city[index][j];}}function changeSelect(index){//选择对象var city = document.form1.city;//修改省份列表的选择项province.selectedIndex = index;//指定城市中<option>标记的个数city.length = arr_city[index].length;//循环将数组中的数据写入<option>标记中for (var j = 0; j<arr_city[index].length;j++) {city.options[j].text = arr_city[index][j];city.options[j].value = arr_city[index][j];}}</script>
2、单选框与下拉框的二级联动
代码：
<!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="">选择一：<input type="radio" name="sel" value="日" id = "sel1"; οnchange="changeSelect(0)">日</input><input type="radio" name="sel" value="每周" οnchange="changeSelect(1)"/>每周</input><input type="radio" name="sel" value="每月" οnchange="changeSelect(2)"/>月</input><br/>选择二：<select name="city" id="city"></select></form></body></html><script type="text/javascript">var arr_time = [["1天","2天","3天","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']];//网页加载完成，初始化菜单window.onload = init;//传入函数地址function init(){console.log(1111);document.getElementById("sel1").checked=true;changeSelect(0);}function changeSelect(index){ //console.log(index)//选择对象var city = document.form1.city;//修改省份列表的选择项//指定城市中<option>标记的个数city.length = arr_time[index].length;//循环将数组中的数据写入<option>标记中for (var j = 0; j<arr_time[index].length;j++) {city.options[j].text = arr_time[index][j];city.options[j].value = arr_time[index][j];}}</script>
