3.点击跳转

 <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.js"></script>
    <style> 
    .container>div{
        height: 400px;
        margin-top: 40px;
    }
    .container>div:nth-child(1){
        background: red;
    }
    .container>div:nth-child(2){
        background: blue;
    }
    .container>div:nth-child(3){
        background: yellow;
    }
    .container>div:nth-child(4){
        background: green;
    }
    .nav{
        position: fixed;
        line-height: 50px;
        background: #eee;;
        top:0;
    }
    </style>

   <div class="nav">
        <a href="#html">html</a>
        <a href="#css">css</a>
        <a href="#js">javascript</a>
        <a href="#vue">vue</a>
    </div>
    <div class="container">
        <div id="html">html</div>
        <div id="css">css</div>
        <div id="js">javascript</div>
        <div id="vue">vue</div>
    </div>
    <script>
        /* obj.offset().top  获取元素距离顶部的距离 
        attr(param)  获取元素的属性
        $('html,body').animate({scrollTop:params})
        */
        $(".nav a").click(function(){
            /* 1.获取当前元素对应跳转的元素距离顶部的高度 */
            var attr = $(this).attr("href");
            var top  = $(attr).offset().top;
            console.log(attr)
            console.log(top)
            /* 2.让窗口滚动对应的高度 */
            $("html,body").animate({scrollTop:top})
            return false;
        })
    </script>