onchange 事件
<body>
<select id="province" onchange="func1()">
<option value="shandong">山东</option>
<option value="hebei">河北</option>
<option value="beijing">北京</option>
</select>
</body>
<script> function func1(){
var pro = document.getElementById("province"); console.log(pro.value) } </script>
使用字典添加数据
一级数据显示
<body>
<select id="province" >
</select>
</body>
<script> data = {
"广东省":["广州","佛山"],"北京":["海淀","廊坊"], "海南省":["三亚","海口"]}; var pro = document.getElementById("province"); for (var i in data){
var option_pro = document.createElement("option"); option_pro.innerHTML=i; pro.appendChild(option_pro); } </script>
二级联动
<body>
<select id="province" onchange="func1(this)" >
</select>
<select id="city"></select>
</body>
<script> data = {
"广东省":["广州","佛山"],"北京":["海淀","廊坊"], "海南省":["三亚","海口"]}; var pro = document.getElementById("province"); var city = document.getElementById("city"); for (var i in data){
var option_pro = document.createElement("option"); option_pro.innerHTML=i; pro.appendChild(option_pro); } function func1(self){
var choice = (self.options[self.selectedIndex]).innerHTML; var options = city.children; for (var k=0; k<options.length; k++){
city.removeChild(options[k--]); } for (var i in data[choice]){
var option_city = document.createElement("option"); option_city.innerHTML = data[choice][i]; city.appendChild(option_city); } } </script>
