js.gif

<!DOCTYPE html>

<head>
    <meta charset="utf-8">
    <title></title>
    <style>
        body{
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
        }
        .box {
            border: 1px solid #333333;
            width: 800px;
            overflow: hidden;/*超出部分隐藏*/
            position: relative;
            height: 200px;
            
        }
        .list{
            display:flex;
            position: absolute;
            left: 0px;
        }
        .list div{
            display: flex;
            justify-content: center;/*行距中*/
            align-items: center;/*列居中*/
            width: 200px;
            height: 200px;
            background-color: #DB7093;
            margin-left: 2px;
            margin-right: 2px;
            font-size: 60px;
            
        }
    </style>
    <script type="text/javascript">
    // 函数入口点
        function load(){
            
            var list=document.querySelector('.list')
            var box=document.querySelector('.box');
            list.innerHTML+=list.innerHTML //复制长度为两倍
            let left=list.style.left; //为list的左距离
            let timer;//为定时器
            // 移动函数 每次-2如果到达第二次的第一个div贴近list的情况下将会left==0,类似于障眼法。
            function move(){
                clearInterval(timer);
                // 定时器开启部分
                timer=setInterval((env)=>{
                    left=left-2;
                    console.log(list.clientLeft);
                    if(left==-(6*200+6*4)){ //指的是每个宽度200有6个加上我的margin宽度
                        left=0;
                    }
                    list.style.left=left+'px';
                },20);
            }
            
                 move();
                 //鼠标放入清楚计时器停止
                box.addEventListener('mouseenter',()=>{
                    clearInterval(timer);
                });
                // 鼠标移出执行一遍定时器继续移动
                box.onmouseleave=function(){
                     move();
                };
        };
        document.addEventListener('DOMContentLoaded',load);
    </script>
</head>
<body>
    <div class="box">
        <div class="list">
            <div>1</div>
            <div>2</div>
            <div>3</div>
            <div>4</div>
            <div>5</div>
            <div class="six_div">6</div>
        </div>
    </div>
</body>