<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>test01</title>
</head>
<body>
<div class="aabb">
<img src="img/cover-1.png" alt="" class="active"/>
<img src="img/cover-1.png" alt="" />
<img src="img/cover-1.png" alt="" />
<img src="img/cover-1.png" alt="" />
<img src="img/cover-1.png" alt="" />
</div>
<script>
let arr=[document.querySelectorAll(".aabb img")];
console.log(arr.length);
for(let i=0;i<=5;i++){
arr[i].classList.toggle('active');
}
</script>
</body>
</html>
