Home >Web Front-end >JS Tutorial >Pure javascript code to implement calculator function (three methods)_javascript skills

Pure javascript code to implement calculator function (three methods)_javascript skills

WBOY
WBOYOriginal
2016-05-16 15:40:151752browse

Today I will share a calculator program written in pure JavaScript code. This program can be used in many industries, such as making decoration budgets, loan interest rates, etc.

First, let’s take a look at the finished effect:

Method 1:

The specific code is as follows:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>计算器</title>
<style type="text/css">
*{margin:0px;padding:0px}
table{width:300px;margin:100px auto}
td{height:30px;text-align:center;line-height:30px;border:1px solid #ccc;font-size:14px} input{float:left;margin-left:30px;display:inline}
#jia,#jian,#cheng,#chu{width:30px}
</style>
<script type="text/javascript">
//以下所有的注释通用语所有的加减乘除算法。
//加法运算
function jia(){
//定义变量a,b,c
var x,y,z;
}; //通过document分别获取x,y的值 x=document.getElementById("num1").value; y=document.getElementById("num2").value; //修改x,y的字符类型,并且得到z的值 z=parseInt(x)+parseInt(y); //将z的值赋给id=result document.getElementById("result").value=z;
//减法运算
function jian(){
var x,y,z;
x=document.getElementById("num1").value;
y=document.getElementById("num2").value;
z=parseInt(x)-parseInt(y);
document.getElementById("result").value=z;
};
//乘法运算
function cheng(){
var x,y,z;
x=document.getElementById("num1").value;
y=document.getElementById("num2").value;
z=parseInt(x)*parseInt(y);
document.getElementById("result").value=z;
};
//除法运算
function chu(){
var x,y,z;
x=document.getElementById("num1").value;
y=document.getElementById("num2").value;
z=parseInt(x)/parseInt(y);
document.getElementById("result").value=z;
};
</script>
</head>
<body>
<table cellpadding="0" cellspacing="0">
<tr>
<td colspan="2">计算器</td>
</tr>
<tr>
<td>数字一</td>
<td><input type="text" id="num1" name="num1"></td>
</tr>
<tr>
<td>数字二</td>
<td><input type="text" id="num2" name="num2"></td>
</tr>
<tr>
<td>结果</td>
<td><input type="text" id="result" name="result"></td>
</tr>
<tr>
<td colspan="2">
<input type="button" name="jia" id="jia" value="+" onclick="jia()"> <input type="button" name="jian" id="jian" value="-" onclick="jian()">
<input type="button" name="cheng" id="cheng" value="×" onclick="cheng()"> <input type="button" name="chu" id="chu" value="/" onclick="chu()"> </td>
</tr>
</table>
</body>
</html>

Code 2:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Javascript实现计算器</title>
<style type="text/css">
input{
width:30px;
height:20px;
text-align:center;
}
#tbCalculator td
{
text-align:center;
vertical-align:middle;
}
</style>
<script type="text/javascript">
var result; //保存点击运算符之前输入框中的数值
var operator; //保存运算符
var isPressEqualsKey = false; //记录是否按下”=“键
//数字键事件
function connectionDigital(control)
{
var txt = document.getElementById('txtScream');
if(isPressEqualsKey)
{ 
txt.value = ""; //已进行过计算,则清空数值输入框重新开始
isPressEqualsKey = false;
}
//数值输入已经存在小数点,则不允许再输入小数点
if(txt.value.indexOf('.') > -1 && control.value == '.')
return false;
txt.value += control.value; //将控件值赋给数值输入框中
}
//退格键事件
function backspace()
{
var txt = document.getElementById('txtScream');
txt.value = txt.value.substring(0,txt.value.length - 1);
}
//ce键事件:清空数字输入框
function clearAll()
{
document.getElementById('txtScream').value = "";
result = "";
operator = "";
}
// +、-、*、/ 事件
function calculation(control)
{
//将运算符保存入全局变量中
operator = control.value; 
var txt = document.getElementById('txtScream');
if(txt.value == "")return false; //数值输入框中没有数字,则不能输入运算符
//将数值输入框中的值保存到计算表达式中
result = txt.value; 
//清空输入框,以待输入操作值
txt.value = ""; 
}
//计算结果
function getResult()
{
var opValue;
//计算表达式中存在运算符
var sourseValue = parseFloat(result);
var txt = document.getElementById('txtScream');
if(operator == '*')
opValue = sourseValue * parseFloat(txt.value);
else if(operator == '/')
opValue = sourseValue / parseFloat(txt.value);
else if(operator == '+')
opValue = sourseValue + parseFloat(txt.value);
else if(operator == '-')
opValue = sourseValue - parseFloat(txt.value);
txt.value = opValue;
isPressEqualsKey = true;
result = "";
opValue = "";
}
</script>
</head>
<body>
<table id="tbCalculator" width="200" border="1" align="center" cellpadding="0" cellspacing="0" bordercolor="#0066FF">
<tr>
<td height="30" colspan="4" align="center">
<input type="text" name="txtScream" id="txtScream" style="width:180px; border-style:none; text-align:right;" readonly="readonly" /> </td>
</tr>
<tr>
<td height="30" colspan="2">
<input type="button" name="btnCE" id="btnCE" value="C E" style="width:80px;" align="right"; onclick="clearAll();" /></td>
<td height="30" colspan="2">
<input type="button" name="btn10" id="btn10" value="Backspace" style="width:80px;" align="right"; onclick="backspace();" /></td>
</tr>
<tr>
<td height="30"><input type="button" name="btn7" id="btn7" value="7" onclick="connectionDigital(this);" /></td>
<td><input type="button" name="btn8" id="btn8" value="8" onclick="connectionDigital(this);"/></td>
<td><input type="button" name="btn9" id="btn9" value="9" onclick="connectionDigital(this);" /></td>
<td><input type="button" name="btn6" id="btn6" value="/" onclick="calculation(this);" /></td>
</tr>
<tr>
<td height="30">
<input type="button" name="btn4" id="btn4" value="4" onclick="connectionDigital(this);"/></td>
<td><input type="button" name="btn5" id="btn5" value="5" onclick="connectionDigital(this);"/></td>
<td><input type="button" name="btn6" id="btn6" value="6" onclick="connectionDigital(this);"/></td>
<td><input type="button" name="btn13" id="btn13" value="*" onclick="calculation(this);" /></td>
</tr>
<tr>
<td height="30">
<input type="button" name="btn1" id="btn1" value="1" onclick="connectionDigital(this);"/></td>
<td><input type="button" name="btn2" id="btn2" value="2" onclick="connectionDigital(this);"/></td>
<td><input type="button" name="btn3" id="btn3" value="3" onclick="connectionDigital(this);"/></td>
<td><input type="button" name="btn18" id="btn18" value="-" onclick="calculation(this);" /></td>
</tr>
<tr>
<td height="30"><input type="button" name="btn0" id="btn0" value="0" onclick="connectionDigital(this);"/></td>
<td><input type="button" name="btndot" id="btndot" value="." onclick="connectionDigital(this);" /></td>
<td><input name="btn22" type="button" id="btn22" value="=" onclick="getResult();" /></td>
<td><input type="button" name="btn23" id="btn23" value="+" onclick="calculation(this);" /></td>
</tr>
</table>
</body>
</html>

Method 3:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
<meta http-equiv="description" content="javascript计算器,由脚本之家制作" /> 
<title>计算器</title> 
<script type="text/javascript"> 
alert("本计算器由脚本之家制作"); 
function getResult(type){ 
if(checkData()){ 
} 
var no1=parseInt(document.jisuanqi.no1.value); 
var no2=parseInt(document.jisuanqi.no2.value); 
var result; 
switch(type){ 
case '+': 
result = no1+no2; 
break; 
case '-': 
result =no1-no2; 
break; 
case '*': 
result =no1*no2; 
break; 
case '/': 
result =no1/no2; 
break; 
case '%': 
result =no1%no2; 
break; 
} 
document.jisuanqi.result.value=result; 
} 
function checkData(){ 
if(document.jisuanqi.no1.value==""){ 
alert("第一个数字不能为空!请重新输入"); 
return; 
} 
if(document.jisuanqi.no2.value==""){ 
alert("第二个不能为空!请重新输入"); 
return; 
} 
if(document.jisuanqi.no1.value=="0"){ 
alert("第一个不能为零!请重新输入"); 
return; 
} 
if(isNaN(document.jisuanqi.no1.value)){ 
alert("第一个不是数字!请重新输入"); 
return; 
} 
if(isNaN(document.jisuanqi.no2.value)){ 
alert("第二个不是数字!请重新输入"); 
} 
} 
</script> 
</head> 
<body> 
<font size="6" color="#000000">本计算器由脚本之家制作<br>QQ:873695957</font> 
<p align="center" /> 
<form name="jisuanqi"> 
  no1:<input name="no1" /><br> 
  no2:<input name="no2" /><br> 
  result:<input name="result" /><br> 
<input type="button" value="+" onclick="getResult('+')" /> 
  <input type="button" value="-" onclick="getResult('-')" /> 
  <input type="button" value="*" onclick="getResult('*')" /> 
  <input type="button" value="/" onclick="getResult('/')" /> 
  <input type="button" value="%" onclick="getResult('%')" /> 
  </form> 
</p> 
</body> 
</html>

The above three methods are used to realize the calculator function using pure javascript code. I hope you like it.

Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn