关于#javascript#的问题，如何解决？
怎么用JavaScript做出来呀大佬们。
代码如下
<style>
/*Basic reset*/
* {
margin: 0;
padding: 0;
box-sizing: border-box;
font: 14px Arial,sans-serif;
}
html {
height: 100%;
}
#calculator {
margin: 15px auto;
width: 325px;
height: 400px;
border: 1px solid lightgray;
background-color: #fff;
padding: 15px;
}
/*LOGO*/
.LOGO {
height: 20px;
}
.LOGO .name {
float: left;
line-height: 30px;
}
.LOGO .verson {
float: right;
line-height: 30px;
}
/*screen*/
#shuRu {
}
.screen {
margin-top: 5px;
width: 295px;
height: 50px;
padding-right: 10px;
font-size: 20px;
}
#keys {
height: 223px;
margin-top: 15px;
}
#keys .last {
margin-right: 0px;
}
.footer {
margin-top: 20px;
height: 20px;
}
.footer .link {
float: right;
}
#keys .buttons {
float: left;
width: 62px;
height: 36px;
text-align: center;
margin: 0 15px 15px 0;
border:solid 1px #333;
border-radius:2px
}
</style>
<body>
<div id="calculator">
<div id="shuRu">
<!--screen输入栏-->
<div class="screen">
<input type="text" id="screenName" name="screenName" class="screen">
</div>
</div>
<div id="keys">
<!-- j -->
<!--第一排-->
<input type="button" id="1" onclick="jsq(this.id)" value="1" class="buttons">
<input type="button" id="2" onclick="jsq(this.id)" value="2" class="buttons">
<input type="button" id="3" onclick="jsq(this.id)" value="3" class="buttons">
<input type="button" id="+" onclick="jsq(this.id)" value="+" class="buttons" style="margin-right:0px">
<!--第二排-->
<input type="button" id="4" onclick="jsq(this.id)" value="4" class="buttons">
<input type="button" id="5" onclick="jsq(this.id)" value="5" class="buttons">
<input type="button" id="6" onclick="jsq(this.id)" value="6" class="buttons">
<input type="button" id="-" onclick="jsq(this.id)" value="-" class="buttons" style="margin-right:0px">
<!--第三排-->
<input type="button" id="7" onclick="jsq(this.id)" value="7" class="buttons">
<input type="button" id="8" onclick="jsq(this.id)" value="8" class="buttons">
<input type="button" id="9" onclick="jsq(this.id)" value="9" class="buttons">
<input type="button" id="*" onclick="jsq(this.id)" value="*" class="buttons" style="margin-right:0px">
<!--第四排-->
<input type="button" id="0" onclick="jsq(this.id)" value="0" class="buttons" style="width:100px">
<input type="button" id="Back" onclick="tuiGe()" value="←" class="buttons" style="width:101px">
<input type="button" id="/" onclick="jsq(this.id)" value="/" class="buttons" style="margin-right:0px">
<!--第五排-->
<input type="button" id="eva" onclick="eva()" value="=" class="buttons" style="width:100%">
<input type="button" id="C" onclick="clearNum()" value="CE" class="buttons" style="width:100%">
</div>
</div>
<script>
var num = 0; // 定义第一个输入的数据
function jsq(num) {
//获取当前输入
if (num == "%") {
document.getElementById('screenName').value = Math.round(document.getElementById('screenName').value) / 100;
} else {
document.getElementById('screenName').value += document.getElementById(num).value;
}
}
function eva() {
//计算输入结果
document.getElementById("screenName").value = document.getElementById("screenName").value+'='+ eval(document.getElementById("screenName").value);
}
function clearNum() {
//清0
document.getElementById("screenName").value = null;
document.getElementById("screenName").focus();
}
function tuiGe() {
//退格
var arr = document.getElementById("screenName");
arr.value = arr.value.substring(0, arr.value.length - 1);
}
</script>
</body>