以下是完整代码
<!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>
<script src="https://how2j.cn/study/jquery.min.js"></script>
<style>
.toTop {
width: 44px;
height: 44px;
border-radius: 50%;
box-shadow: 0px 4px 10px 0px rgba(0, 0, 0, 0.24);
position: fixed;
bottom: 48px;
right: 12px;
text-align: center;
}
</style>
</head>
<body>
<div id="toTop" class="toTop">回到顶部</div>
</body>
</html>
<script>
for (var i = 0; i < 200; i++) {
$('body').append(i + '<br />')//为了使看的更清楚，给页面添加点元素
}
$('#toTop').click(function () {
$('html').animate({ scrollTop: 0 }, 500)//页面滚动效果
})
</script>
