Write a javascript program to make a simple calculator
- 11 Answers
- 67870 Views
- Anand Group, TCS, I also Faced
- E-Mail Answers
Answer Posted / 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 |
Post New Answer View All Answers
Is javascript whitespace sensitive?
Is JavaScript case sensitive? Give an example?
What is the use of a set object in javascript?
What are the characteristics of javascript ‘strict mode’?
Is Exception handling possible in Javascript?
How can an HTMLCollection be traversed?
How long does it take to learn javascript?
How to capture the Image width and height using QTP script ? Kindly answer plz.... Thanx in adavance...
What are decodeuri() and encodeuri() functions in javascript?
What is the difference between an array and an object?
How to calculate fibonacci numbers in javascript?
How to write a function in javascript?
How do you add an element at the beginning of an array?
How to load another html page from javascript?
Is there an alternative to javascript?
