任务描述：鼠标点击不同商品类别标题时切换不同页面

html代码：

<div class="tab">
        <div class="tab-head">
            <h3>家电</h3>
            <ul>
                <li><a class="active" href="javascript:;">热门</a></li>
                <li><a href="javascript:;">电视影音</a></li>
                <li><a href="javascript:;">电脑</a></li>
                <li><a href="javascript:;">家居</a></li>
            </ul>
        </div>
        <div class="tab-content">
            <div class="item active"><img src="./tab01.png" alt="" /></div>
            <div class="item"><img src="./tab02.png" alt="" /></div>
            <div class="item"><img src="./tab03.png" alt="" /></div>
            <div class="item"><img src="./tab04.png" alt="" /></div>
        </div>
    </div>

css代码：

<style>
        *{
            margin: 0;
            padding: 0;
        }
        .tab{
            width: 600px;
            height: 350px;
            margin: 20px;
            border: 1px solid #e4e4e4;
        }
        .tab-head{
            width: 100%;
            height: 60px;
            line-height: 60px;
            display: flex;
            justify-content: space-between;
        }
        .tab-head h3{
            font-size: 25px;
            font-weight: normal;
            margin-left: 20px;
        }
        .tab-head ul{
            list-style: none;
            display: flex;
            justify-content: flex-end;
        }
        .tab-head ul li{
            margin: 0px 20px;
            font-size: 15px;
        }
        .tab-head ul li a{
            text-decoration: none;
            border-bottom: 2px solid transparent;
            color: #000000;
        }
        .tab-head ul li a.active{
            border-color: #ff7f00;
            color:#ff7f00;
        }
        .tab-content{
            padding: 0px 15px;
        }
        .tab-content .item{
            display: none;
        }
        .tab-content .item img{
            width: 100%;
            height: 100%;
        }
        .tab-content .item.active{
            display: block;
        }
    </style>

js代码：

<script>
      const title = document.querySelectorAll('.tab-head a')
      for(let i = 0; i < title.length; i++){
         title[i].addEventListener('mouseover',function(){
         document.querySelector('.tab-head .active').classList.remove('active')
         this.classList.add('active')
         document.querySelector('.tab-content .active').classList.remove('active')
         document.querySelector(`.tab-content .item:nth-child(${i + 1})`).classList.add('active')
         })
      }
    </script>

运行效果：