<!DOCTYPE HTML>
<html>
<head>
<title>联动菜单</title>
<meta charset="utf-8" />
<script>
/*使用 HTML DOM 的方式实现联动菜单*/
var categories=[
{
"id":10,
"name":'男装',
"children":[
{"id":101,"name":'正装'},
{"id":102,"name":'T恤'},
{"id":103,"name":'裤衩'}
]
},
{
"id":20,
"name":'女装',
"children":[
{"id":201,"name":'短裙'},
{"id":202,"name":'连衣裙'},
{
"id":203,
"name":'裤子',
"children": [
{"id":2031,"name":'长裤'},
{"id":2031,"name":'九分裤'},
{"id":2031,"name":'七分裤'}
]
},
]
},
{"id":30,"name":'童装',"children":[
{"id":301,"name":'帽子'},
{"id":302,"name":'套装',"children":[
{"id":3021,"name":"0-3岁"},
{"id":3021,"name":"3-6岁"},
{"id":3021,"name":"6-9岁"},
{"id":3021,"name":"9-12岁"}
]},
{"id":303,"name":'手套'}
]}
];
</script>
</head>
<body>
<div id="category"></div>
<script>
//查找id为category的div保存在div中
var div=document.getElementById("category");
//定义函数createSelect,接收一个数组参数arr
function createSelect(arr){
//创建一个select
var sel=document.createElement("select");
//创建一个option，设置其内容为"-请选择-"，值为-1,将option添加到select中
sel.add(new Option("--请选择--",-1));
//遍历arr
for(var i=0;i<arr.length;i++){
//创建一个option，设置内容为当前元素的name属性，设置value为当前元素的id属性，将新option添加到select中
sel.add(new Option(arr[i].name,arr[i].id));
}//(遍历结束)
//为sel绑定onchange事件
sel.onchange=function(){
//反复:只要当前select不是div的lastChild
while(this!=div.lastChild)
//让div删除其lastChild
div.removeChild(div.lastChild);
//获得当前选中项的下表-1，保存在i中
var i=this.selectedIndex-1;
//如果arr中i位置的商品类别有children
if(i>=0&&arr[i].children!==undefined)
//用arr中i位置的商品类别的children数组创建下一个select
createSelect(arr[i].children);
}
//将select添加到div中
div.appendChild(sel);
}
createSelect(categories);
</script>
</body>
</html>
