js滚动到从顶部动画

js
scrollToptimer = setInterval(function () {
console.log("定时循环回到顶部")
var top = document.body.scrollTop || document.documentElement.scrollTop;
var speed = top / 4;
if (document.body.scrollTop!=0) {
document.body.scrollTop -= speed;
}else {
document.documentElement.scrollTop -= speed;
}
if (top == 0) {
clearInterval(scrollToptimer);
}
}, 30);

jquery

js滚动到从顶部动画最先出现在Python成神之路。