页面内跳转到相应位置的3种方法

        .demo{
            width: 200px;
            height: 200px;
            border: 1px red solid;
            margin-bottom: 100px;
            margin-right: 50px;
        }
        .btn{
            position: fixed;
            right: 0;
            top: 20px;
            background-color: #0000cc;
            color: #ffffff;
        }

<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo" id="demo">这个DIV，id是demo</div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>
<div class="demo"></div>

<!--1.使用a标签跳转到对应id的位置-->
<a href="#demo">跳到id为demo的DIV</a>

<!--2.通过btn的window.location.hash  跳转到对应位置-->
<input  type="button" value="跳到id为demo的DIV"  onclick="javascript:onTopClick();" />

    function onTopClick() {
        window.location.hash = "#domo";
    }

<button class="btn"> 到指定滚动高度</button>

$(document).on('click',$('.btn'),function(){
        $(window).scrollTop($('#demo').offset().top)
    })