<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>JavaScript Study</title>
</head>
<style>
#One,#Two,#Three{
140px!important;
height:40px!important;
background: pink!important;
color:#fff!important;
padding-left:30px;
}
</style>
<body>
<select id="One" onChange="changeTwoSel()" title=""></select>
<select id="Two" onchange="changeThreeSel()" title=""></select>
<select id="Three" title=""></select>
<script>;
var oneArray=['请选择','上衣','裙装','鞋子'];
var twoArray =[['请选择'],['羽绒服','棉服','妮子外套'],['长裙','短裙','A字裙'],['帆布鞋','短靴','长靴']];
var threeArray =[
[['请选择']],
[['白羽绒','黑羽绒','灰羽绒'],['黑棉服','白棉服','灰棉服'],['黑妮子','白妮子','灰妮子']],
[['白长裙','黑长裙','灰长裙'],['黑短裙','白短裙','灰短裙'],['黑A裙','白A裙','灰A裙']],
[['白布鞋','黑布鞋','灰布鞋'],['黑短靴','白短靴','灰短靴'],['黑长靴','白长靴','灰长靴']]
];
var oneSel = document.getElementById("One");
var twoSel = document.getElementById('Two');
var threeSel = document.getElementById('Three');
var str = '';
//下拉框一初始选项
for (var i = 0; i < oneArray.length; i++) {
str += "<option value='" + i + "'>" + oneArray[i] + "</option>";
}
oneSel.innerHTML = str;
str = '';
//下拉框二初始选项
for (var i = 0; i < twoArray[0].length; i++) {
str += "<option value='" + i + "'>" + twoArray[0][i] + "</option>";
}
twoSel.innerHTML = str;
str = '';
//下拉框三初始选项
for (var i = 0; i < threeArray[0].length; i++) {
str += "<option>" + threeArray[0][0][i] + "</option>";
}
threeSel.innerHTML = str;
//动态改变下拉框二选项
function changeTwoSel() {
twoSel.innerHTML = '';
str = '';
var twoSelValue = parseInt(oneSel.value);
try {
for (var i = 0; i < twoArray[twoSelValue].length; i++) {
str += "<option value='" + i + "'>" + twoArray[twoSelValue][i] + "</option>";
}
} catch (ex) {
str = "<option>无选项</option>";
}
twoSel.innerHTML = str;
changeThreeSel();
}
//动态改变下拉框三选项
function changeThreeSel() {
threeSel.innerHTML = '';
str = '';
var twoSelValue = parseInt(oneSel.value);
var threeSelValue = parseInt(twoSel.value);
try {
for (var i = 0; i < threeArray[twoSelValue][threeSelValue].length; i++) {
str += "<option value='" + i + "'>" + threeArray[twoSelValue][threeSelValue][i] + "</option>";
}
} catch (ex) {
str = "<option>无选项</option>";
}
threeSel.innerHTML = str;
}
</script>
</body>
</html>