<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css" >
.xuanx{
width: 600px;
height: 300px;
background-color: red;
}
.clearfix:after{
content: '';
visibility:hidden;
height: 0;
clear:both;
display: block;
}
.nav a{
color: #fff;
text-decoration: none;
height: 30px;
width: 200px ;
line-height: 30px;
text-align:center;
display: inline-block;
background-color: #000;
float: left;
}
.content{
width: 600px;
height: 270px;
background-color: blue;
}
.content div{
display: none;
}
</style>
</head>
<body>
<div class="xuanx">
<div class="nav clearfix " id = 'link'>
<a href="javascript:void(0)">标题1</a>
<a href="javascript:void(0)">标题2</a>
<a href="javascript:void(0)">标题3</a>
</div>
<div class="content" id = 'link-centent'>
<div style='display: block;'>
<span>内容1</span>
</div>
<div >
<span>内容2</span>
</div>
<div >
<span>内容3</span>
</div>
</div>
</div>
<script type="text/javascript">
var Aparent = document.getElementById('link');
var Achild = Aparent.getElementsByTagName('a');
var Div = document.getElementById('link-centent');
var Divs = Div.getElementsByTagName('div');
for(let i = 0;i<Achild.length;i++){
// Achild[i].index = i; 这里是用var的解决方法，将每一次循环的索引进行存储，后面进行直接调用
Achild[i].onclick = function(){
for(var j=0;j<Achild.length;j++){
Achild[j].style='';
Divs[j].style='';
}
this.style.color= 'red';
this.style.backgroundColor='blue';
// Divs[this.index].style.display='block';
Divs[i].style.display='block';
}
}
</script>
</body>
</html>
