制作类似分享插件功能

$(".side ul li:not('.backTop')").hover(function() {
        $(this).find(".sideBox").stop().animate({
            "width" : "90px",
        }, 300);
    }, function() {
        $(this).find(".sideBox").stop().animate({
            "width" : "35px"
        }, 300);
    });
    
    $("#backTop").on('click',goTop);
//回到顶部函数
function goTop(){
    $('html,body').animate({'scrollTop':0},300);
}

<div class="side">
        <ul>
            <li><a href="#">
                    <div class="sideBox">
                        <span class="icon-fullscreen"></span>返回首页
                    </div>
            </a></li>
            <li><a href="#">
                    <div class="sideBox">
                        <span class="icon-helpFeedback"></span>帮助反馈
                    </div>
            </a></li>
            <li class="backTop"><a id="backTop" href="#">
                    <div class="sideBox">
                        <span class="icon-backTop"></span>
                    </div>
            </a></li>
        </ul>
    </div>

.side {
    position: fixed;
    right: 0;
    bottom: 50px;
    width: 35px;
    z-index: 1000;
}

.side>ul {
    margin: 0;
    padding: 0;
}

.side>ul>li {
    width: 35px;
    height: 42px;
    position: relative;
    padding: 8px;
    margin-top:10px;
}

.side>ul>li>a {
    font-size: 12px;
}

.side>ul>li>a>div {
    border: 1px solid #e8e8e8;
    border-right: none;
    border-radius: 5px 0 0 5px;
}

.side>ul>li .sideBox {
    position: absolute;
    width: 35px;
    height: 42px;
    top: 0;
    right: 0;
    overflow: hidden;
    line-height:43px;
}

.sidetip-txt {
    display: none;
}

.sideBox-show {
    width: 35px;
    height: 42px;
}

.icon-fullscreen {
    line-height: 0;
    height: 40px;
    width:30px;
    display: inline-block;
    vertical-align: middle;
    border: 0 none;
    outline: none;
    background-color: transparent;
    background-repeat: no-repeat;
    background-attachment: scroll;
    background-image: url("/resources/img/users/md_hyzx_wdsc.png");
    line-height: 0;
    background-position: -339px 13px;
}
.icon-helpFeedback{
    line-height: 0;
    height: 40px;
    width:30px;
    display: inline-block;
    vertical-align: middle;
    border: 0 none;
    outline: none;
    background-color: transparent;
    background-repeat: no-repeat;
    background-attachment: scroll;
    background-image: url("/resources/img/users/md_hyzx_wdsc.png");
    line-height: 0;
    background-position: -339px -38px;
}
.icon-backTop{
    line-height: 0;
    height: 40px;
    width:30px;
    display: inline-block;
    vertical-align: middle;
    border: 0 none;
    outline: none;
    background-color: transparent;
    background-repeat: no-repeat;
    background-attachment: scroll;
    background-image: url("/resources/img/users/md_hyzx_wdsc.png");
    line-height: 0;
    background-position: -339px -83px;
}