<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
body {
margin: 0;
padding: 0;
}
ul {
display: flex;
justify-content: space-around;
align-items: center;
border: 2px solid red;
list-style: none;
}
ul>li {
width: 100%;
text-align: center;
border-right: 2px solid red;
cursor: pointer;
}
ul>li:last-child {
border-right: 0;
}
.active {
background-color: #ccc;
}
div>p {
display: none;
}
.currenty {
display: block;
}
</style>
</head>
<body>
<ul>
<li class="active">1</li>
<li>2</li>
<li>3</li>
<li>4</li>
</ul>
<div>
<p class="currenty">11</p>
<p>22</p>
<p>33</p>
<p>44</p>
</div>
<script>
let aLi = document.querySelectorAll('li')
let aP = document.querySelectorAll('p')
let index = 0;
for (var i = 0; i < aLi.length; i++) {
(function(i){
aLi[i].onclick=function(){
aLi[index].className = ''
aP[index].className = ''
index = i
aLi[index].className = 'active'
aP[index].className = 'currenty'
}
})(i)
}
</script>
</body>
</html>
