Js implementation of imitating Sina Weibo back to the top In the web page, if the page is high, in order to facilitate the user to quickly return to the top, a return to top button will be added. On Taobao, the back to top button is displayed only when the scroll distance of the scroll bar is greater than a certain distance; The return top of Renren is directly on the toolbar at the bottom; The return top of Sina Weibo is displayed when the rolling height is greater than 0, and the return top effect is a smooth animation effect. The realization of this article is similar to the effect of Sina Weibo. Sina Weibo has launched a new domain name weibo.com two thousand and eleven five thousand three hundred and fifty-nine
