计算器页面的JS实现

<section>
    <input /><br />
    <div class="opt">(</div>
    <div class="opt">)</div>
    <div class="opt">%</div>
    <div class="opt">C</div>
    <div>7</div>
    <div>9</div>
    <div>8</div>
    <div class="opt">/</div>
    <div>4</div>
    <div>5</div>
    <div>6</div>
    <div class="opt">*</div>
    <div>1</div>
    <div>2</div>
    <div>3</div>
    <div class="opt">-</div>
    <div>0</div>
    <div>.</div>
    <div>=</div>
    <div class="opt">+</div>
    <section>
<script>
    var ipt=document.querySelector("input");
    var divs=document.querySelectorAll("div");
    for(let i=0;i<divs.length;i++){
        var item=divs[i];
        if(item.innerHTML!="C"&&item.innerHTML!="="){
            item.onclick=function(){
                ipt.value=item.innerHTML;
            }
            else if(item.innerHTML=="C"){
                ipt.value=""
            }
            else{
                var n=eval(ipt.value);
                ipt.value=n;
            }
        }
    }


</script>