<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>javascript 添加元素</title>
<script type="text/javascript" src="jquery-1.4.2.min.js"></script>
<style type="text/css">
*{ padding:0; margin:0}
body{overflow: hidden;}
.wrap{position: relative;width: 300px;height: 200px;margin: 30px auto}
.wrap .btn {}
.wrap .btn li{list-style: none;margin: 0 5px;float: left;list-style: none;}
</style>
</head>
<body>
<div class="wrap">
<div class="btn">
<a class="on">广州</a>
<a>上海</a>
<a>湛江</a>
<a>草潭</a>
<a>遂溪</a>
</div>
<ul id="con"></ul>
</div>
<script type="text/javascript">
var a = document.getElementsByTagName("a");
var ul = document.getElementById("con");
var li = ul.getElementsByTagName("li");
for (var i = 0; i < a.length;i++){
// a[i].index = i; 获取当前索引
a[i].onclick = function(){
if(checkTxt(this.innerHTML)){
var oLi = document.createElement("li");
oLi.innerHTML = this.innerHTML;
if(!li[0]){
ul.appendChild(oLi);
}else{
ul.insertBefore(oLi,li[0]);
}
}else{
checkTxt2(this.innerHTML);
}
}
}
function checkTxt(text){ //检测添加的元素有没有存在
var result = true;
for (var i = 0 ; i < li.length;i++){
if( li[i].innerHTML == text){
result = false;
}
};
return result;
}
function checkTxt2(text){ //第二次点击元素的时候。重新排序
for (var i = 0 ; i < li.length;i++){
if( li[i].innerHTML == text){
ul.insertBefore(li[i],li[0]);
}
};
}
</script>
</body>
</html>
