Write a javascript program to make a simple calculator




Answers were Sorted based on User's Feedback



Write a javascript program to make a simple calculator..

Answer / raghu

Actually we already known simple calculator means such like
addition, subraction,division, multiplication.those things
are coding by switch case method.

Is This Answer Correct ?    114 Yes 44 No

Write a javascript program to make a simple calculator..

Answer / anusha

<html>
<head>
<title>A simple JavaScript calculator</title>
<script language='JavaScript'>
Default = "0";
Current = "0";
Operation = 0;
MaxLength = 30;

function AddDigit(dig) {
if (Current.indexOf("!") == -1) {
if ((eval(Current) == 0) && (Current.indexOf(".") == -1)) {
Current = dig;
} else {
Current = Current + dig;
}
Current = Current.toLowerCase();
} else {
Current = "Hint! Press 'AC'";
}
if (Current.indexOf("e0") != -1) {
var epos = Current.indexOf("e");
Current = Current.substring(0,epos+1) + Current.substring(epos+2);
}
if (Current.length > MaxLength) {
Current = "Too long";
}
document.Calculator.Display.value = Current;
}

function Dot() {
if ( Current.length == 0) {
Current = "0.";
} else {
if (( Current.indexOf(".") == -1) && (Current.indexOf("e") == -1)) {
Current = Current + ".";
}
}
document.Calculator.Display.value = Current;
}

function DoExponent() {
if ( Current.indexOf("e") == -1 ) {
Current = Current + "e0";
document.Calculator.Display.value = Current;
}
}

function PlusMinus() {
if(Current.indexOf("e") != -1) {
var epos = Current.indexOf("e-");
if (epos != -1) {
Current = Current.substring(0,1+epos) + Current.substring(2+epos);
} else { epos = Current.indexOf("e");
Current = Current.substring(0,1+epos) + "-" + Current.substring(1+epos);
}
} else {
if ( Current.indexOf("-") == 0 ) {
Current = Current.substring(1);
} else {
Current = "-" + Current;
}
if ((eval(Current) == 0) && (Current.indexOf(".") == -1 )) {
Current = "0"; }
}
document.Calculator.Display.value = Current;
}

function Clear() {
Current = "0";
document.Calculator.Display.value = Current;
}

function AllClear() {
Current = "0";
Operation = 0;
Default = "0";
document.Calculator.Display.value = Current;
}

function Operate(op) {
if (Operation != 0) { Calculate(); };
if (op.indexOf("*") > -1) { Operation = 1; };
if (op.indexOf("/") > -1) { Operation = 2; };
if (op.indexOf("+") > -1) { Operation = 3; };
if (op.indexOf("-") > -1) { Operation = 4; };

Default = Current;

Current = "";
document.Calculator.Display.value = Current;
}

function Calculate() {
if (Operation == 1) { Current = eval(Default) * eval(Current); };
if (Operation == 2) {
if (eval(Current) != 0) {
Current = eval(Default) / eval(Current)
} else {
Current = "Divide by zero";
}
}
if (Operation == 3) { Current = eval(Default) + eval(Current); };
if (Operation == 4) { Current = eval(Default) - eval(Current); };
Operation = 0;
Default = "0";
Current = Current + "";
if (Current.indexOf("Infinity") != -1) {
Current = "Value too big";
}
if (Current.indexOf("NaN") != -1) {
Current = "I don't understand";
}
document.Calculator.Display.value = Current;
}

function FixCurrent() {
Current = document.Calculator.Display.value;
Current = "" + parseFloat(Current);
if (Current.indexOf("NaN") != -1) {
Current = "I don't understand";
}
document.Calculator.Display.value = Current;
}
</script>

</head>
<hr><div align="center">
<FORM name="Calculator">
<table width="40%" height="40%" border="4" bgcolor="#FFEBCD"><tr>
<td colspan="2" align="center">
<b><font face="Verdana, Arial, Helvetica" color="#000080" size="3">
A Simple JavaScript Calculator<br></font>
<font face="Courier" size="5">
<input type="text" maxlength="40" size="25" name="Display" onChange="FixCurrent()">
</font></b>
</td></tr>
<tr><td width="65%" align="center">
<table><tr>
<td><input type="button" name="seven" value=" 7 " OnClick="AddDigit('7')"></td>
<td><input type="button" name="eight" value=" 8 " OnClick="AddDigit('8')"></td>
<td><input type="button" name="nine" value=" 9 " OnClick="AddDigit('9')"></td>
</tr><tr>
<td><input type="button" name="four" value=" 4 " OnClick="AddDigit('4')"></td>
<td><input type="button" name="five" value=" 5 " OnClick="AddDigit('5')"></td>
<td><input type="button" name="six" value=" 6 " OnClick="AddDigit('6')"></td>
</tr><tr>
<td><input type="button" name="one" value=" 1 " OnClick="AddDigit('1')"></td>
<td><input type="button" name="two" value=" 2 " OnClick="AddDigit('2')"></td>
<td><input type="button" name="three" value=" 3 " OnClick="AddDigit('3')"></td>
</tr><tr>
<td><input type="button" name="plusmin" value=" +/- " OnClick="PlusMinus()"></td>
<td><input type="button" name="one" value=" 0 " OnClick="AddDigit('0')"></td>
<td><input type="button" name="two" value=" . " OnClick="Dot()"></td>
</tr>
</table>
</td>
<td width="35%" align="center">
<table><tr>
<td><input type="button" name="clear" value=" C " OnClick="Clear()"></td>
<td><input type="button" name="AC" value=" AC " OnClick="AllClear()"></td>
</tr><tr>
<td><input type="button" name="mul" value=" * " OnClick="Operate('*')"></td>
<td><input type="button" name="div" value=" / " OnClick="Operate('/')"></td>
</tr><tr>
<td><input type="button" name="add" value=" + " OnClick="Operate('+')"></td>
<td><input type="button" name="sub" value=" - " OnClick="Operate('-')"></td>
</tr><tr>
<td><input type="button" name="result" value=" = " OnClick="Calculate()"></td>
<td align="right"><input type="button" name="exp" value=" EXP " OnClick="DoExponent()"></td>
</tr></table>
</td>
</tr></table>
</div></body>
</html>

Is This Answer Correct ?    68 Yes 26 No

Write a javascript program to make a simple calculator..

Answer / raghav seth

html>
<form name="calculator">
<table border=4>
<tr>
<td>
<input type="text" name="text" size="18">
<br>
</td>
</tr>
<tr>
<td>
<input type="button" value="1" onclick="calculator.text.value += '1'">
<input type="button" value="2" onclick="calculator.text.value += '2'">
<input type="button" value="3" onclick="calculator.text.value += '3'">
<input type="button" value="+" onclick="calculator.text.value += ' + '">
<br>
<input type="button" value="4" onclick="calculator.text.value += '4'">
<input type="button" value="5" onclick="calculator.text.value += '5'">
<input type="button" value="6" onclick="calculator.text.value += '6'">
<input type="button" value="-" onclick="calculator.text.value += ' - '">
<br>
<input type="button" value="7" onclick="calculator.text.value += '7'">
<input type="button" value="8" onclick="calculator.text.value += '8'">
<input type="button" value="9" onclick="calculator.text.value += '9'">
<input type="button" value="*" onclick="calculator.text.value += ' * '">
<br>
<input type="button" value="c" onclick="calculator.text.value = ''">
<input type="button" value="0" onclick="calculator.text.value += '0'">
<input type="button" value="=" onclick="calculator.text.value = eval(calculator.text.value)">
<input type="button" value="/" onclick="calculator.text.value += ' / '">
<br>
</td>
</tr>
</table>
</form>
</html>

Is This Answer Correct ?    62 Yes 20 No




Write a javascript program to make a simple calculator..

Answer / rehan

<html>
<head><title>Calculator</title>
<script language="javascript">
var inputstring=" "
function updatestring(value)
{
inputstring += value;
document.calculator.input.value=inputstring;
}
</script>
</head>
<body background=flow-yellow.jpg>
<form name="calculator">
<table border=5 bordercolor=pink bgcolor="#ffffcc"><tr ><td>
<input type="text" name="input" maxlength=15 size=27><br />
<input type="button" value=" clear " onclick="input.value=' ';inputstring=' ' ">
<input type="button" value=" mod " onclick="updatestring('%')">
<input type="button" value=" * " onclick="updatestring('*')"><br />
<input type="button" value=" 7 " onclick="updatestring('7')">
<input type="button" value=" 8 " onclick="updatestring('8')">
<input type="button" value=" 9 " onclick="updatestring('9')">
<input type="button" value=" / " onclick="updatestring('/')"><br />
<input type="button" value=" 4 " onclick="updatestring('4')">
<input type="button" value=" 5 " onclick="updatestring('5')">
<input type="button" value=" 6 " onclick="updatestring('6')">
<input type="button" value=" - " onclick="updatestring('-')"><br />
<input type="button" value=" 1 " onclick="updatestring('1')">
<input type="button" value=" 2 " onclick="updatestring('2')">
<input type="button" value=" 3 " onclick="updatestring('3')">
<input type="button" value=" + " onclick="updatestring('+')"><br />
<input type="button" value=" 0 " onclick="updatestring('0')">
<input type="button" value=" 00 " onclick="updatestring('00')">
<input type="button" value=" . " onclick="updatestring('.')">
<input type="button" value=" = " onclick="input.value=eval(inputstring);">
</td></tr>
</table>
</form>
</body>
</html>

Is This Answer Correct ?    31 Yes 12 No

Write a javascript program to make a simple calculator..

Answer / ruchi goswami

<html>
<head>
<link rel="stylesheet" type="text/css" href="css2.css">
<title> calculator </title>
</head>

<body>
<div id="wrap">
<h1> Calculator </h1>
<b> enter first number </b>
&nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp
<b> enter second number </b>
<form action="">
<input type="text" name="firstnum" id="first">
&nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp
<input type="text" name="lastnum" id="second">
</form>

<br> </br>
<button onclick="sum()"> + </button>
&nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp
<button onclick="sub()"> - </button>
&nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp
<button onclick="mul()"> * </button>
&nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp
<button onclick="divi()"> / </button>
<br> </br>
<input type="text" id="result">




<p id="demo"></p>
<script>
function sum()
{
var a = Number(document.getElementById("first").value);
var b = Number(document.getElementById("second").value);
c = a+b;
document.getElementById("result").value = c;

}
function sub()
{
var a = Number(document.getElementById("first").value);
var b = Number(document.getElementById("second").value);
c = a-b;
document.getElementById("result").value = c;

}

function mul()
{
var a = Number(document.getElementById("first").value);
var b = Number(document.getElementById("second").value);
c = a*b;
document.getElementById("result").value = c;

}

function divi()
{
var a = Number(document.getElementById("first").value);
var b = Number(document.getElementById("second").value);
c = a/b;
document.getElementById("result").value = c;

}
</script>


</div>
</body>
</html>

Is This Answer Correct ?    12 Yes 1 No

Write a javascript program to make a simple calculator..

Answer / vinoth180

var a=20;
var b=11;
document.writeln("ADDITION:",a+b,"<br>");
document.writeln("SUB:",a-b,"<br>");
document.writeln("MUL:",a*b,"<br>");
document.writeln("MUL:",a%b,"<br>");

Is This Answer Correct ?    43 Yes 33 No

Write a javascript program to make a simple calculator..

Answer / mehta fenil & bodiwala rum

<html>
<head>
<title>Basic Calculator</title>
<script language="JavaScipt" type="text/JavaScript">
var adddigit=false;
var oldval=0;
var op="=";

function btnconcat(c)
{
if(adddigit)
{
document.getElementById("txtdisplay").value+=c;
}
else
{
document.getElementById("txtdisplay").value=c;
adddigit=true;
}
}

function operation(newop)
{
var newarg=eval(document.getElementById("txtdisplay").value)
if(op=="+")
{
oldval=oldval+newarg;
}
else if(op=="-")
{
oldval=oldval-newarg;
}
else if(op=="*")
{
oldval=oldval*newarg;
}
else if(op=="/")
{
oldval=oldval/newarg;
}
else if(op=="=")
{
oldval=newarg;
}
else
{
oldval=newarg;
}
document.getElementById("txtdisplay").value=oldval;
adddigit=false;
op=newop;
}

function backspace()
{

document.getElementById("txtdisplay").value=document.getElementById("txtdisplay").value.substring(0,document.getElementById("txtdisplay").value.length*1-1);
}

function btnce()
{
document.getElementById("txtdisplay").value="";
}

function btnc()
{
document.getElementById("txtdisplay").value=0;
oldval=0;
adddigit=false;
op="=";
}
</script>
</head>
<body>
<center>
<table border=5 cellpading=5 cellspacing=5>

<tr>
<td colspan="4"><input type="text" id="txtdisplay"
size="25" style="text-align:right"></td>
</tr>

<tr>
<td>
<center>
<input type="button" id="btnc" value="C"
onClick="btnc();">
</center>
</td>

<td>&nbsp;

</td>

<td>
<center>
<input name="Button" type="button" id="btnc"
onClick="btnce();" value="CE">
</center>
</td>

<td>
<center>
<input type="button" id="btnc" value="<="
onClick="backspace();">
</center>
</td>
</tr>

<tr>
<td>
<center>
<input type="button" id="btn7" value="7"
onClick="btnconcat(7);">
</center>
</td>

<td>
<center>
<input type="button" id="btn8" value="8"
onClick="btnconcat(8);">
</center>
</td>

<td>
<center>
<input type="button" id="btn9" value="9"
onClick="btnconcat(9);">
</center>
</td>

<td>
<center>
<input type="button" id="btnpls" value="+"
onClick="operation('+');">
</center>
</td>
</tr>

<tr>
<td>
<center>
<input type="button" id="btn4" value="4"
onClick="btnconcat(4);">
</center>
</td>

<td>
<center>
<input type="button" id="btn5" value="5"
onClick="btnconcat(5);">
</center>
</td>

<td>
<center>
<input type="button" id="btn6" value="6"
onClick="btnconcat(6);">
</center>
</td>

<td>
<center>
<input type="button" id="btnmin" value="-"
onClick="operation('-');">
</center>
</td>
</tr>

<tr>
<td>
<center>
<input type="button" id="btn1" value="1"
onClick="btnconcat(1);">
</center>
</td>

<td>
<center>
<input type="button" id="btn2" value="2"
onClick="btnconcat(2);">
</center>
</td>

<td>
<center>
<input type="button" id="btn3" value="3"
onClick="btnconcat(3);">
</center>
</td>

<td>
<center>
<input type="button" id="btnmul" value="*"
onClick="operation('*');">
</center>
</td>
</tr>

<tr>
<td>
<center>
<input type="button" id="btnpoi" value="."
onClick="btnconcat('.');">

</center>
</td>

<td>
<center>
<input type="button" id="btn0" value="0"
onClick="btnconcat(0);">
</center>
</td>

<td>
<center>
<input type="button" id="btneql" value="="
onClick="operation(value)">
</center>
</td>

<td>
<center>
<input type="button" id="btndiv" value="/"
onClick="operation('/');">
</center>
</td>
</tr>

</table>
</center>
</body>
</html>

Is This Answer Correct ?    12 Yes 3 No

Write a javascript program to make a simple calculator..

Answer / san

<html>
<form name="cals">
<table border=1>
<tr>
<td>
<input type="text" name="text" size=15>
</td>
</tr>
<br>
<tr>
<td>
<input type="button" value="1" onclick="cals.text.value +='1'">
<input type="button" value="2" onclick="cals.text.value +='2'">
<input type="button" value="3" onclick="cals.text.value +='3'">
<input type="button" value="+" onclick="cals.text.value +='+'">
<br>
<input type="button" value="4" onclick="cals.text.value +='4'">
<input type="button" value="5" onclick="cals.text.value +='5'">
<input type="button" value="6" onclick="cals.text.value +='6'">
<input type="button" value="- " onclick="cals.text.value +='-'">
<br>
<input type="button" value="7" onclick="cals.text.value +='7'">
<input type="button" value="8" onclick="cals.text.value +='8'">
<input type="button" value="9" onclick="cals.text.value +='9'">
<input type="button" value="*" onclick="cals.text.value +='*'">
<br>
<input type="button" value="c" onclick="cals.text.value =''">
<input type="button" value="0" onclick="cals.text.value +='0'">
<input type="button" value="=" onclick="cals.text.value = eval(cals.text.value)">
<input type="button" value="/" onclick="cals.text.value +=' /'">
<br>
</td>
</tr>
</table>
</form>
</html>

Is This Answer Correct ?    11 Yes 7 No

Write a javascript program to make a simple calculator..

Answer / krishna

<html>
<form name="calculator">
<table border=4>
<tr>
<td>
<input type="text" name="text" size="18">
<br>
</td>
</tr>
<tr>
<td>
<input type="button" value="1" onclick="calculator.text.value += '1'">
<input type="button" value="2" onclick="calculator.text.value += '2'">
<input type="button" value="3" onclick="calculator.text.value += '3'">
<input type="button" value="+" onclick="calculator.text.value += ' + '">
<br>
<input type="button" value="4" onclick="calculator.text.value += '4'">
<input type="button" value="5" onclick="calculator.text.value += '5'">
<input type="button" value="6" onclick="calculator.text.value += '6'">
<input type="button" value="-" onclick="calculator.text.value += ' - '">
<br>
<input type="button" value="7" onclick="calculator.text.value += '7'">
<input type="button" value="8" onclick="calculator.text.value += '8'">
<input type="button" value="9" onclick="calculator.text.value += '9'">
<input type="button" value="*" onclick="calculator.text.value += ' * '">
<br>
<input type="button" value="c" onclick="calculator.text.value = ''">
<input type="button" value="0" onclick="calculator.text.value += '0'">
<input type="button" value="=" onclick="calculator.text.value = eval(calculator.text.value)">
<input type="button" value="/" onclick="calculator.text.value += ' / '">
<br>
</td>
</tr>
</table>
</form>
</html>

Is This Answer Correct ?    8 Yes 5 No

Write a javascript program to make a simple calculator..

Answer / s.suresh

<html>
<form name="calculator">
<table border=4>
<tr>
<td>
<input type="text" name="text" size="18">
<br>
</td>
</tr>
<tr>
<td>
<input type="button" value="1"
onclick="calculator.text.value += '1'">
<input type="button" value="2"
onclick="calculator.text.value += '2'">
<input type="button" value="3"
onclick="calculator.text.value += '3'">
<input type="button" value="+"
onclick="calculator.text.value += ' + '">
<br>
<input type="button" value="4"
onclick="calculator.text.value += '4'">
<input type="button" value="5"
onclick="calculator.text.value += '5'">
<input type="button" value="6"
onclick="calculator.text.value += '6'">
<input type="button" value="-"
onclick="calculator.text.value += ' - '">
<br>
<input type="button" value="7"
onclick="calculator.text.value += '7'">
<input type="button" value="8"
onclick="calculator.text.value += '8'">
<input type="button" value="9"
onclick="calculator.text.value += '9'">
<input type="button" value="*"
onclick="calculator.text.value += ' * '">
<br>
<input type="button" value="c"
onclick="calculator.text.value = ''">
<input type="button" value="0"
onclick="calculator.text.value += '0'">
<input type="button" value="="
onclick="calculator.text.value = eval(calculator.text.value)">
<input type="button" value="/"
onclick="calculator.text.value += ' / '">
<br>
</td>
</tr>
</table>
</form>
</html>

Is This Answer Correct ?    10 Yes 8 No

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