jQuery实例 - 返回顶部

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .divH {
            height: 1800px;
        }
        .divT {
            width: 50px;
            height: 50px;
            font-size: 23px;
            background-color: #2F4F4F;
            color: white;
            position: fixed;
            right: 18px;
            bottom: 18px;
        }
        .divT:hover{
            cursor: pointer;
        }
        .hide {
            display: none;
        }
    </style>
</head>
<body>
    <div></div>
    <div class="divT hide" onclick="ReturnTop();"><strong>返回顶部</strong></div>

    <script src="../../jquery-1.12.4.js"></script>
    <script>
        window.onscroll = function () {
            var current = $(window).scrollTop();
            if (current > 180){
                $(".divT").removeClass("hide");
            }else {
                $(".divT").addClass("hide");
            }
        };

        function ReturnTop() {
            $(window).scrollTop(0);
        }
    </script>
</body>
</html>
一个人值不值得你穷极一生去喜欢，不是看他能对你有多好，而是看他心情不好的时候能对你有多差。