

我想实现一个图像轮播以及按钮实现切换上下张图片,我这段代码有什么问题吗?
你的引入js文件不应该放在head中,要放在body中引入:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" href="css/river.css">
<title>Document</title>
</head>
<body>
<div class="lb">
<button class="pre"><</button>
<div class="lb-img">
<img src="./1.png" id="num1" width="700" height="300" alt="">
<img src="./2.png" id="num2" width="700" height="300" alt="">
</div>
<button class="next">></button>
</div>
<script type="text/javascript" src="js/river.js"></script>
</body>
</html>