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JS制作簡單的三級聯動

 本文給大家分享的是使用javascript實現的一個簡單的三級聯動菜單,非常簡單實用,有需要的小伙伴過來參考下吧。

   

用javascript制作的一個簡單三級聯動,非常簡單實用

 

代碼如下:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
省:
<select style="width: 100px;" id="pre" onchange="chg(this);">
<option value="-1">請選擇</option>
</select>
市:
<select style="width: 100px;" id="city" onchange="chg2(this)" ;></select>
區:
<select style="width: 100px;" id="area"></select>
</body>
<script>
//聲明省
var pres = ["北京", "上海", "山東"]; //直接聲明Array
//聲明市
var cities = [
["東城", "昌平", "海澱"],
["浦東", "高區"],
["濟南", "青島"]
];
var areas = [
[
["東城1", "東城2", "東城3"],
["昌平1", "昌平2", "昌平3"],
["海澱1", "海澱2", "海澱3"]
],
[
["浦東1", "浦東2", "浦東3"],
["高區1", "高區2", "高區3"]
],
[
["濟南1", "濟南2"],
["青島1", "青島2"]
]
]
//設置一個省的公共下標
var pIndex = -1;
var preEle = document.getElementById("pre");
var cityEle = document.getElementById("city");
var areaEle = document.getElementById("area");
//先設置省的值
for (var i = 0; i < pres.length; i++) {
//聲明option.<option value="pres[i]">Pres[i]</option>
var op = new Option(pres[i], i);
//添加
preEle.options.add(op);
}
function chg(obj) {
if (obj.value == -1) {
cityEle.options.length = 0;
areaEle.options.length = 0;
}
//獲取值
var val = obj.value;
pIndex = obj.value;
//獲取ctiry
var cs = cities[val];
//獲取默認區
var as = areas[val][0];
//先清空市
cityEle.options.length = 0;
areaEle.options.length = 0;
for (var i = 0; i < cs.length; i++) {
var op = new Option(cs[i], i);
cityEle.options.add(op);
}
for (var i = 0; i < as.length; i++) {
var op = new Option(as[i], i);
areaEle.options.add(op);
}
}
function chg2(obj) {
var val = obj.selectedIndex;
var as = areas[pIndex][val];
areaEle.options.length = 0;
for (var i = 0; i < as.length; i++) {
var op = new Option(as[i], i);
areaEle.options.add(op);
}
}
</script>
</html>

 

以上所述就是本文的全部內容了,希望大家能夠喜歡。

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