移动端返回顶部右下角按钮代码

html结构：------------------------------------------------------------------

<div class="go-top">返回顶部</div>

css样式：----------------------------------------------------------------------

.go-top {
    position: fixed;
    bottom: 10px;
    right: 10px;
    background: #fff;
    display: none;
    cursor: pointer;
}

js代码：----------------------------------------------------------------------

window.onscroll=function(){
    if($(window).scrollTop()>100){
         $('.go-top').show();
    }else{
         $('.go-top').hide();
    }
}
$('.go-top').click(function(){
    scroll('0px', 300);

});
function scroll(scrollTo, time) {
    var scrollFrom = parseInt(document.body.scrollTop),
        i = 0,
        runEvery = 5; // run every 5ms

    scrollTo = parseInt(scrollTo);
    time /= runEvery;

    var interval = setInterval(function () {
        i++;

        document.body.scrollTop = (scrollTo - scrollFrom) / time * i + scrollFrom;

        if (i >= time) {
            clearInterval(interval);
        }
    }, runEvery);
}