Калькулятор на JavaScript

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Родительская категория: Web разработка
Категория: JavaScript (примеры и задачи)






 

Листинг файла calc.html

 

<HTML>
<head>
<title>Calculator</title>
<center>
<script language="LiveScript">
<!--
function addChar(input, character)
{if(input.value == null || input.value == "0")
 input.value = character
 else
 input.value += character
}
function cos(form)
{form.display.value = Math.cos(form.display.value);}

function sin(form)
{form.display.value = Math.sin(form.display.value);}

function tan(form)
{form.display.value = Math.tan(form.display.value);}

function sqrt(form)
{form.display.value = Math.sqrt(form.display.value);}

function ln(form)
{form.display.value = Math.log(form.display.value);}

function exp(form)
{form.display.value = Math.exp(form.display.value);}

function sqrt(form)
{form.display.value = Math.sqrt(form.display.value);}

function deleteChar(input)
{input.value = input.value.substring(0, input.value.length - 1);}

function changeSign(input)
{// could use input.value = 0 - input.value, but let's show off substring
 if(input.value.substring(0, 1) == "-")
 input.value = input.value.substring(1, input.value.length)
 else
 input.value = "-" + input.value
}

function compute(form) 
{form.display.value = eval(form.display.value);}

function square(form) 
{form.display.value = eval(form.display.value) * eval(form.display.value);}

function checkNum(str) 
{ for (var i = 0; i < str.length; i++) {
 var ch = str.substring(i, i+1)
 if (ch < "0" || ch > "9") {
 if (ch != "/" && ch != "*" && ch != "+" && ch != "-" && ch != "."
 && ch != "(" && ch!= ")") {
 alert("invalid entry!")
 return false
 }
 }
 }
 return true
}
//-->
</script>
</head>
<BODY BGCOLOR="#000000" TEXT="#FFFFFF" LINK="#33FF00" VLINK="#CC0000" ALINK="#3300FF">
<font size=+1>Javascript Calculator</font>
<hr>
<form>
<input name="display" value="0" size=25></td>
<br>

<input type="button" value=" exp "
 onClick="if (checkNum(this.form.display.value)){ exp(this.form) }">

<input type="button" value=" 7 "
 onClick="addChar(this.form.display, '7')">
<input type="button" value=" 8 "
 onClick="addChar(this.form.display, '8')">
<input type="button" value=" 9 "
 onClick="addChar(this.form.display, '9')">
<input type="button" value=" / "
 onClick="addChar(this.form.display, '/')">
<br>

<input type="button" value=" ln "
 onClick="if (checkNum(this.form.display.value)){ ln(this.form) }">

<input type="button" value=" 4 "
 onClick="addChar(this.form.display, '4')">
<input type="button" value=" 5 "
 onClick="addChar(this.form.display, '5')">
<input type="button" value=" 6 "
 onClick="addChar(this.form.display, '6')">
<input type="button" value=" * "
 onClick="addChar(this.form.display, '*')">
<br>

<input type="button" value=" sqrt "
 onClick="if (checkNum(this.form.display.value))
{ cos(this.form) }">
<input type="button" value=" 1 "
 onClick="addChar(this.form.display, '1')">
<input type="button" value=" 2 "
 onClick="addChar(this.form.display, '2')">
<input type="button" value=" 3 "
 onClick="addChar(this.form.display, '3')">
<input type="button" value=" - " 
 onClick="addChar(this.form.display, '-')">
<br>

<input type="button" value=" sq "
 onClick="if (checkNum(this.form.display.value)) { square(this.form) }">
<input type="button" value=" 0 "
 onClick="addChar(this.form.display, '0')"> 
<input type="button" value=" . "
 onClick="addChar(this.form.display, '.')"> 
<input type="button" value=" +/- "
 onClick="changeSign(this.form.display)">
<input type="button" value=" + "
 onClick="addChar(this.form.display, '+')">

<br>
<input type="button" value=" ( "
 onClick="addChar(this.form.display, '(')"> 
 
<input type="button" value=" cos "
 onClick="if (checkNum(this.form.display.value)){ cos(this.form) }">

<input type="button" value=" sin "
 onClick="if (checkNum(this.form.display.value)){ sin(this.form) }">

<input type="button" value=" tan "
 onClick="if (checkNum(this.form.display.value)){ tan(this.form) }">

<input type="button" value=" ) "
 onClick="addChar(this.form.display, ')')">

<br>

<input type="button" value=" Clear "
 onClick="this.form.display.value = 0 ">

<input type="button" value=" Back Space "
 onClick="deleteChar(this.form.display)">

<input type="button" value=" Enter " name="enter"
 onClick="if (checkNum(this.form.display.value)) { compute(this.form) }">
</form>
</HTML>