<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<script type="text/javascript">
function toTop() {
var scrollToTop=setInterval(function() {
var pos = window.pageYOffset;
if ( pos >1 ) {
window.scrollTo(0, pos - pos/15 );
} else {
window.scrollTo(0,0);
window.clearInterval( scrollToTop );
}
}, 10);
}
</script>
<div style="position: fixed; bottom: 10px; right: 10px; cursor: pointer; color: blue" onclick="toTop()">返回顶部</div>
<script type="text/javascript">
for (i=0;i<2000;i++){
document.write("<br>");
}
</script>
</body>
</html>
原文：https://www.cnblogs.com/gigigigi/p/14689302.html