用js编写的简单的计算器代码程序
投稿：lijiao
这篇文章主要介绍了用js编写的简单的计算器代码程序，非常具有实用性,感兴趣的小伙伴可以参考下
最近编写的一个简单的计算器代码程序，先给大家展示一下
分享代码如下
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title></title>
<style type="text/css">
#box{width: 295px; margin: 0 auto; text-align: justify; border: 1px solid #ddd; padding: 15px;}
.d_num{display: inline-block; margin: 10px; width: 33px; height: 30px; border: 1px solid #ddd; text-align: center; line-height: 30px; cursor: pointer;}
.sum{margin: 0 10px 10px; line-height: 30px; font-size: 20px;}
#sum{width: 205px; height: 30px; padding: 0 5px; margin-left: 5px; font-size: 20px;}
#process{width: 255px; height: 30px; padding: 0 5px; margin-left: 5px; font-size: 20px;}
</style>
</head>
<body>
<div id="box">
<div class="sum">
<input type="text" name="process" id="process" value="0" />
</div>
<div class="sum">
SUM:<input type="text" name="sum" id="sum" value="0" />
</div>
<div>
<span data-num="1" class="d_num">1</span>
<span data-num="2" class="d_num">2</span>
<span data-num="3" class="d_num">3</span>
<span data-num="<-" class="d_num"><-</span>
<span data-num="C" class="d_num">C</span>
</div>
<div>
<span data-num="4" class="d_num">4</span>
<span data-num="5" class="d_num">5</span>
<span data-num="6" class="d_num">6</span>
<span data-num="*" class="d_num">*</span>
<span data-num="/" class="d_num">/</span>
</div>
<div>
<span data-num="7" class="d_num">7</span>
<span data-num="8" class="d_num">8</span>
<span data-num="9" class="d_num">9</span>
<span data-num="+" class="d_num">+</span>
<span data-num="-" class="d_num">-</span>
</div>
<div>
<span data-num="0" class="d_num">0</span>
<span data-num="00" class="d_num">00</span>
<span data-num="." class="d_num">.</span>
<span data-num="%" class="d_num">%</span>
<span data-num="=" class="d_num">=</span>
</div>
</div>
<script type="text/javascript">
var $box = document.getElementById('box');
var $sum = document.getElementById('sum');
var $process = document.getElementById('process');
var sum = 0, process = '', num1 = '', num2 = '', temp = '', statu = false;
$box.onclick = function(e){
var event = window.event || e;
var ele = event.srcElement || event.target;
var _className = ele.className;
if(_className == 'd_num'){
var num = ele.getAttribute('data-num');//点击的按钮对应的值
var NotNum = isNaN(num);
if(!NotNum || num == '.'){ //点击了数字
if(!statu){ //还没点击过符号
if(num1 == '0'){
num1 = '';
}
num1 += num;
process = num1;
}else{ //已经点击过符号
if(num2 == '0'){
num2 = '';
}
num2 += num;
process = num1 + temp + num2;
}
$process.value = process;
}
else{ //点击了符号
if(num1 == ''){//非法操作
return false;
}
if(num == 'C'){//归零
num1 = '';
num2 = '';
process = '';
temp = '';
sum = '';
$process.value = '0';
$sum.value = '0';
statu = false;
return false;
}
if(num == '<-'){//退档
if(sum != ''){
return false;
}
if(num2 == ''){
; num1 = num1.substring(0,num1.length-1);
if(num1 == ''){
num1 = '0';
}
process = num1;
$process.value = process;
}else{
num2 = num2.substring(0,num2.length-1);
if(num2 == ''){
num2 = '0';
}
process = num1 + temp + num2;
$process.value = process;
}
return false;
}
if(num2 != ''){//a&b
if(num == '='){//元操作到此结束
$process.value = process;
}else{
$process.value = process + num;
}
switch(temp){//元操作继续
case '+' : sum = parseFloat(num1) + parseFloat(num2); $sum.value = sum; $process.value = process; num1 = sum + ''; num2 = ''; break;
case '-' : sum = parseFloat(num1) - parseFloat(num2); $sum.value = sum; $process.value = process; num1 = sum + ''; num2 = ''; break;
case '*' : sum = parseFloat(num1) * parseFloat(num2); $sum.value = sum; $process.value = process; num1 = sum + ''; num2 = ''; break;
case '/' : sum = parseFloat(num1) / parseFloat(num2); $sum.value = sum; $process.value = process; num1 = sum + ''; num2 = ''; break;
case '%' : sum = parseFloat(num1) % parseFloat(num2); $sum.value = sum; $process.value = process; num1 = sum + ''; num2 = ''; break;
}
}else{//a&？
if(num == '='){
return false;
}
$process.value = process + num;
process = '';
}
if(num == '='){
sum = '';
statu = false;
return false;
}
temp = num;//记录操作符
statu = true;//已经触发操作状态
}
}
};
</script>
</div>
</body>
</html>
现在只是个简单的标准计算器，能进行加减乘除连续运算，以及求余运算。如果发生被除数为零的错误，下面会给出提示，就像这样：
这就是我设计的一个小程序，还有许多改进的地方，比如界面的美化，会再接再厉。
以上就是本文的全部内容，希望对大家的学习有所帮助。