<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>onchange事件</title>
<script>
//封装document.getElemenyById();
function $(id) {
return document.getElementById(id);
}
</script>
</head>
<body>
<script>
//sel改变时发生的操作
function bian(){
//1声明二维数组
var city=[
["哈尔滨","齐齐哈尔","牡丹江"],
["长春","吉林","四平"],
["沈阳","丹东","大连"]
];
//2获取sel的值
var value=$("sel").value;
if(value==-1){
var html="<option>请先选择省份</option>"
$("sel_city").innerHTML=html;
}else{
var Acity=city[value];
//循环遍历city数组,拼option字符串
var htmlcity="";
for (var i=0;i<city.length;i++) {
htmlcity+="<option>";
htmlcity+=Acity[i];
htmlcity+="</option>";
}
//拼好的字符串放sel_city里
$("sel_city").innerHTML=htmlcity;
}
}
</script>
<select id="sel" onchange="bian()">
<option value="-1">请选择省份</option>
<option value="0">黑龙江</option>
<option value="1">吉林</option>
<option value="2">辽宁</option>
</select>
<select id="sel_city"></select>
</body>
</html>