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console 命令行工具 X clear

                    
>
console
const arr =new Array(10).join("+-")
console.log(arr)
<div class="contain">
        <div class="box">hello</div>
 </div>

 <div class="contain1">
        <div class="box1">hello</div>
 </div>
.contain{
    width: 100px;
    height: 100px;
    border:1px solid;
    display: flex;
    justify-content: center;
    align-items: center;
     background: red;
     opacity: 0.5

  
   
}
.box{
    width: 50px;
    height: 50px;
    border:1px solid
}
.contain1{
    width: 100px;
    height: 100px;
    border:1px solid;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: rgba(255, 0, 0, 0.5)

}
.box1{
    width: 50px;
    height: 50px;
    border:1px solid
}