DOCTYPE html>
html>
    head>
        meta charset="utf-8" />
        meta name="viewport" content="width=device-width, initial-scale=1">
        title>title>
        script src="jquery-3.5.1.min.js" type="text/javascript" charset="utf-8">script>

        style type="text/css">
            #box {
                background-color: red;
                height: 300px;
                width: 300px;
            }
        style>

        script type="text/javascript">
            $(document).ready(function() {
                $("#s-top-get").click(function() {
                    $("p").text("scrollTop()获取" + $(document).scrollTop());
                });
                $("#s-top-set").click(function() {
                    $(document).scrollTop(70);
                });
            });
        script>
    head>
    body>
        div id="box">
        div>

        button type="button" id="s-top-get">scrollTop()获取button>
        button type="button" id="s-top-set">scrollTop()设置button>

        p>p>
    body>
html>