var getTop = document.getElementById("get-top");
var head = document.getElementById("head");
getTop.onclick = function () {
var time = setInterval(function () {
document.body.scrollTop = document.body.scrollTop - 50;
if (document.body.scrollTop === 0) {
clearInterval(time);
}
}, 1);
};
链接:https://segmentfault.com/q/1010000003855799