js键盘实现键盘输入计算器_用js代码做一个简易计算器

1. 用js 代码做一个简易计算器

functiontest(){
vartxt1=document.getElementById("txt1"),
txt2=document.getElementById("txt2"),
txt3=document.getElementById("txt3"),
opt=document.getElementById("sel");
txt3.value=eval(txt1.value+opt.value+txt2.value);//eval函数可计算某个字符串，并执行其中的的js代码
}

<inputtype="text"id="txt1"/>
<selectid="sel">
<optionvalue="+">+</option>
<optionvalue="-">-</option>
<optionvalue="*">*</option>
<optionvalue="/">/</option>
</select>
<inputtype="text"id="txt2"/>
=
<inputtype="text"id="txt3"/>
<inputtype="button"id="btn"value="计算"onclick="test()"/>

2. 用javaScript做一个简易的计算器

我刚学javaScript做一计算器，请看看！多多交流！~~``

<html>
<head>
<title>计算器</title>
</head>
<body bgcolor="#33FF99" onload="FKeyPad.ReadOut.focus();FKeyPad.ReadOut.select();">
<FORM name="Keypad" action="">
<TABLE align="center">
<B>
<TABLE align="center" border=3 width=60 height=80 cellpadding=2 cellspacing=5 borderlight="#008080">
<tr align="center">
<td bordercolor="#FF33CC" bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933" colspan=10 align=center>网页计算器</td>
</tr>
<tr align="center">
<td bordercolor="#FF33CC" bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933" colspan=10 align=right><input name="ReadOut" type="Text" onkeypress="CheckOut()" size=40 value="0"
width=100%></td>
</tr>
<tr align="center">
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnsin" type="Button" value=" sin " onclick="useFun ('sin')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btncos" type="Button" value=" cos " onclick="useFun ('cos')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnOne" type="Button" value=" 1 " onclick="NumPressed(1)"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnTwo" type="Button" value=" 2 " onclick="NumPressed(2)"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnThree" type="Button" value=" 3 " onclick="NumPressed(3)"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnPlus" type="Button" value=" + " onclick="Operation('+')"> </td>
</tr>
<tr align="center">
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnasin" type="Button" value=" asin " onclick="useFun ('asin')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnacos" type="Button" value=" acos " onclick="useFun ('acos')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnFour" type="Button" value=" 4 " onclick="NumPressed(4)"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnFive" type="Button" value=" 5 " onclick="NumPressed(5)"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnSix" type="Button" value=" 6 " onclick="NumPressed(6)"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnMinus" type="Button" value=" - " onclick="Operation('-')"></td>
</tr>
<tr align="center">
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btntan" type="Button" value=" tan " onclick="useFun ('tan')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnatan" type="Button" value=" atan " onclick="useFun ('atan')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnSeven" type="Button" value=" 7 " onclick="NumPressed(7)"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnEight" type="Button" value=" 8 " onclick="NumPressed(8)"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnNine" type="Button" value=" 9 " onclick="NumPressed(9)"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnMultiply" type="Button" value=" * " onclick="Operation('*')"></td>
</tr>
<tr align="center">
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnlog" type="Button" value=" log " onclick="useFun ('log')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnexp" type="Button" value=" exp " onclick="useFun ('exp')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnZero" type="Button" value=" 0 " onclick="NumPressed(0)"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnDecimal" type="Button" value=" . " onclick="Decimal()"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnNeg" type="Button" value=" +/- " onclick="Neg()"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnDivide" type="Button" value=" / " onclick="Operation('/')"></td>
</tr>
<tr align="center">
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnsqrt" type="Button" value=" sqrt " onclick="useFun ('sqrt')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnOx" type="Button" value=" 1/x " onclick="useFun ('1/x')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnXt" type="Button" value=" x^2 " onclick="useFun ('x^2')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnXthr" type="Button" value=" x^3 " onclick="useFun ('x^3')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnpi" type="Button" value=" pi " onclick=FKeyPad.ReadOut.value=Math.PI></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnEquals" type="Button" value=" = " onclick="Operation('=')"></td>
</tr>
<tr align="center">
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnDivide" type="Button" value=" N! " onclick="ni ()"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnDivide" type="Button" value=" pow " onclick="Operation('pow')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnDivide" type="Button" value=" E " onclick=FKeyPad.ReadOut.value=Math.E></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnClear" type="Button" value=" C " onclick="Clear()"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnClearEntry" type="Button" value=" CE " onclick="ClearEntry()"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnReturn" type="Button" value="返回" onclick="goReturn()"></td>
</tr>
<tr align="center">
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnmod" type="Button" value=" MOD " onclick="Operation('MOD')"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnDivide" type="Button" value=" INT" onclick=FKeyPad.ReadOut.value=parseInt(FKeyPad.ReadOut.value,10)></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnmod" type="Button" value=" HEX " onclick="hexchange ()"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnmod" type="Button" value=" OCT " onclick="octchange ()"></td>
<td bordercolordark="#cc0066" bordercolor="#FF9966" bordercolorlight="#CC9933"><input name="btnmod" type="Button" value=" BIN " onclick="binchange ()"></td>
</tr>
</TABLE>
</TABLE>
</B>
</FORM>
</CENTER>
<font face="Verdana, Arial, Helvetica" size=2>
<SCRIPT LANGUAGE="JavaScript">

</SCRIPT>
</body>
</html>

3. 加法计算器：编程由键盘输入两个整数a和b，计算出它们的和并输出到屏幕上

方法一：

#include<stdio.h>

int main()

{

int a,b，c;

c=a+b;

scanf("%d %d",&a,&b);

printf("a+b=%d", c);

return 0;

}

方法二：

var a,b:longint;begin readln(a,b); writeln(a+b);end.

c#编写加法计算器

static void Main(string[] args)

{

bool flag = true;

Console.WriteLine("请输入第一个加数:");

float num = 0;

float sum = 0;

if (float.TryParse(Console.ReadLine(), out num))

flag = false;

Console.WriteLine("错误，输入的不是数字！程序结束。");

Console.WriteLine("请输入第二个加数:");

if (float.TryParse(Console.ReadLine(), out num))

flag = false;

Console.WriteLine("错误，输入的不是数字！程序结束。");

Console.Read();

if (flag)

{

Console.WriteLine("两数的和是：{0}", sum.ToString());

Console.Read();

}

整除特征

1、若一个数的末位是单偶数，则这个数能被2整除。

2、若一个数的所有数位上的数字和能被3整除，则这个整数能被3整除。

3、若一个数的末尾两位数能被4整除，则这个数能被4整除。

4、若一个数的末位是0或5，则这个数能被5整除。

5、若一个数能被2和3整除，则这个数能被6整除。

以上内容参考：网络-整数

4. 如何使用JS编写一个简单的计算器

js部分
var num=0,result=0,numshow="0";
var operate=0; //判断输入状态的标志
var calcul=0; //判断计算状态的标志
var quit=0; //防止重复按键的标志
function command(num){
var str=String(document.calculator.numScreen.value); //获得当前显示数据
str=(str!="0") ? ((operate==0) ? str : "") : ""; //如果当前值不是"0"，且状态为0，则返回当前值，否则返回空值;
str=str + String(num); //给当前值追加字符
document.calculator.numScreen.value=str; //刷新显示
operate=0; //重置输入状态
quit=0; //重置防止重复按键的标志
}
function dzero(){
var str=String(document.calculator.numScreen.value);
str=(str!="0") ? ((operate==0) ? str + "00" : "0") : "0"; //如果当前值不是"0"，且状态为0，则返回当str+"00"，否则返回"0";
document.calculator.numScreen.value=str;
operate=0;
}
function dot(){
var str=String(document.calculator.numScreen.value);
str=(str!="0") ? ((operate==0) ? str : "0") : "0"; //如果当前值不是"0"，且状态为0，则返回当前值，否则返回"0";
for(i=0; i<=str.length;i++){ //判断是否已经有一个点号
if(str.substr(i,1)==".") return false; //如果有则不再插入
}
str=str + ".";
document.calculator.numScreen.value=str;
operate=0;
}
function del(){ //退格
var str=String(document.calculator.numScreen.value);
str=(str!="0") ? str : "";
str=str.substr(0,str.length-1);
str=(str!="") ? str : "0";
document.calculator.numScreen.value=str;
}
function clearscreen(){ //清除数据
num=0;
result=0;
numshow="0";
document.calculator.numScreen.value="0";
}
function plus(){ //加法
calculate(); //调用计算函数
operate=1; //更改输入状态
calcul=1; //更改计算状态为加
}
function minus(){ //减法
calculate();
operate=1;
calcul=2;
}
function times(){ //乘法
calculate();
operate=1;
calcul=3;
}
function divide(){ //除法
calculate();
operate=1;
calcul=4;
}
function persent(){ //求余
calculate();
operate=1;
calcul=5;
}
function equal(){
calculate(); //等于
operate=1;
num=0;
result=0;
numshow="0";
}
//
function calculate(){
numshow=Number(document.calculator.numScreen.value);
if(num!=0 && quit!=1){ //判断前一个运算数是否为零以及防重复按键的状态
switch(calcul){ //判断要输入状态
case 1:result=num+numshow;break; //计算"+"
case 2:result=num-numshow;break; //计算"-"
case 3:result=num*numshow;break;
case 4:if(numshow!=0){result=num/numshow;}else{document.getElementById("note").innerHTML="被除数不能为零！"; setTimeout(clearnote,4000)} break;
case 5:result=num%numshow;break;
}
quit=1; //避免重复按键
}
else{
result=numshow;
}
numshow=String(result);
document.calculator.numScreen.value=numshow;
num=result; //存储当前值
}
function clearnote(){ //清空提示
document.getElementById("note").innerHTML="";
}

html部分：
<!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>写给新手：js表单操作（四）简单计算器（二）</title>
<style type="text/css">
body {
font-size:12px;
font-family:Arial, Georgia, "Times New Roman", Times, serif;
color:#555;
text-align:center;
background-color:#e2e2e2;
}
h6{
margin:0;
font-size:12px;
}
#calculator {
width:240px;
height:auto;
overflow:hidden;
margin:10px auto;
border:#fff 1px solid;
padding-bottom:10px;
background-color:#f2f2f2;
}
#calculator div {
clear:both;
}
#calculator ul{
padding:0;
margin:5px 14px;
border:#fff 1px solid;
height:auto;
overflow:hidden
}
#calculator li{
list-style:none;
float:left;
width:32px;
height:32px;
margin:5px;
display:inline;
line-height:32px;
font-size:14px;
background-color:#eaeaea;
}
#calculator li.tool{
background-color:#e2e2e2;
}
#calculator li:hover{
background-color:#f9f9f9;
cursor:pointer;
}
#calculator li:active{
background-color:#fc0;
cursor:pointer;
}
#calculator li.tool:active{
background-color:#d8e8ff;
cursor:pointer;
}
#calcu-head {
text-align:left;
padding:10px 15px 5px;
}
span.imyeah {
float:right;
color:#ccc;
}
span.imyeah a{
color:#ccc;
}
.screen{
width:200px;
height:24px;
line-height:24px;
padding:4px;
border:#e6e6e6 1px solid;
border-bottom:#f2f2f2 1px solid;
border-right:#f2f2f2 1px solid;
margin:10px auto;
direction:ltr;
text-align:right;
font-size:16px;
color:#999;
}
#calcu-foot{
text-align:left;
padding:10px 15px 5px;
height:auto;
overflow:hidden;
}
span#note{
float:left;
width:210px;
height:auto;
overflow:hidden;
color:red;
}
span.welcome{
clear:both;
color:#999;
}
span.welcome a{
float:right;
color:#999;
}
</style>
<script language="javascript">
//此处插入上面的js代码
</script>
</head>
<body>
<div id="calculator">
<div id="calcu-head"><span class="imyeah">© <a href="http://www.cnblogs.com/imyeah/" target="_blank">I'm Yeah!</a></span><h6>简单的计算器</h6></div>
<form name="calculator" action="" method="get">
<div id="calcu-screen">

<input type="text" name="numScreen" class="screen" value="0" onfocus="this.blur();" />
</div>
<div id="calcu-btn">
<ul> 
<li onclick="command(7)">7</li>
<li onclick="command(8)">8</li>
<li onclick="command(9)">9</li>
<li class="tool" onclick="del()">←</li>
<li class="tool" onclick="clearscreen()">C</li>
<li onclick="command(4)">4</li>
<li onclick="command(5)">5</li>
<li onclick="command(6)">6</li>
<li class="tool" onclick="times()">×</li>
<li class="tool" onclick="divide()">÷</li>
<li onclick="command(1)">1</li>
<li onclick="command(2)">2</li>
<li onclick="command(3)">3</li>
<li class="tool" onclick="plus()">+</li>
<li class="tool" onclick="minus()">-</li>
<li onclick="command(0)">0</li>
<li onclick="dzero()">00</li>
<li onclick="dot()">.</li>
<li class="tool" onclick="persent()">%</li>
<li class="tool" onclick="equal()">=</li>
</ul>
</div>
<div id="calcu-foot">
<span id="note"></span>
<span class="welcome">欢迎使用javascript计算器！<a href="http://www.cnblogs.com/imyeah" target="_blank">反馈</a></span>
</div>
</form>
</div>
</body>
</html>

5. js计算器代码怎么写,通过弹窗显示

js计算器代码，通过弹窗显示步骤如下。
1、js计算器代码编写html，实现计算器页面视图效果。
2、js计算器代码编写，实现点击输入数字和符号输出结果。
3、js计算器代码创建click1函数，判断flag的值，如果是true就定位到第一个输入框，如果是false就定位到第二个输入框，将点击传过来的值与输入框里面的字符串拼接到一起。
4、js计算器代码定义result函数，定位到两个输入框，取出其中的值并转成整数，定位到隐藏输入框，取出里面的符号，然后判断是什么符号，进行相应的运算，弹出运算结果。

导航:首页 > 编程语言 > js键盘实现键盘输入计算器

js键盘实现键盘输入计算器

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