用JavaScript做一个简易的计算器
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简易计算器为十进制计算器，能进行整数和小数的十进制加、减、乘、除四则运算；
2、计算器中设有复位键和退格键，复位键功能是一个算术过程完成后，将计算器清0，为下一次算术过程的开始作准备；退格键的功能是输入过程出错时可进行删除。
<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">
<!-- Begin
var FKeyPad = document.forms[\'Keypad\'];
var Accum = "0";
var FlagNewNum = false;
var PendingOp = "";
function longCount(str1,str2,type)
var comma1 = 0;
if (str1.indexOf(".")!=-1)
str1 = str1.replace(/0*$/,"");
comma1 = str1.length - str1.indexOf(".")-1;
var comma2 = 0;
if (str2.indexOf(".")!=-1)
str2 = str2.replace(/0*$/,"");
comma2 = str2.length - str2.indexOf(".")-1;
str1 = str1.replace(/\\./,"");
str2 = str2.replace(/\\./,"");
var value,comma;
if (type!="*")
if (comma1>comma2)
for (var i=0;i<comma1-comma2;i++) str2 += "0";
comma = (type=="/")?0:comma1;
else
for (var i=0;i<comma2-comma1;i++) str1 += "0";
comma = (type=="/")?0:comma2;
else
comma = comma1 + comma2;
if (type=="+")
value = parseInt(str1,10) + parseInt(str2,10);
else if (type=="-")
value = parseInt(str1,10) - parseInt(str2,10);
else if (type=="*")
value = parseInt(str1,10) * parseInt(str2,10);
else if (type=="/")
value = parseInt(str1,10) / parseInt(str2,10);
else if (type=="MOD")
value = parseInt(str1,10) % parseInt(str2,10);
else if (type=="pow")
var a,b,s=1;
a=parseInt(str1,10);
b=parseInt(str2,10);
for(var i=1;i<=b;i++)
s=s*a;
value=parseInt(s,10);
value = String(value);
if (comma>0) value = value.substring(0,value.length-comma)+"."+value.substring(value.length- comma,value.length);
if (value.indexOf(".")!=-1)
value = value.replace(/0*$/,"");
return value;
function NumPressed (Num)
if (FlagNewNum)
FKeyPad.ReadOut.value = Num;
FlagNewNum = false;
else
if (FKeyPad.ReadOut.value == "0")
FKeyPad.ReadOut.value = Num;
else
FKeyPad.ReadOut.value += Num;
function Operation (Op)
var Readout = FKeyPad.ReadOut.value;
if (FlagNewNum && PendingOp != "=");
else
FlagNewNum = true;
if ( \'+\' == PendingOp || \'-\' == PendingOp || \'/\' == PendingOp || \'*\' == PendingOp||\'MOD\'==PendingOp||\'pow\'==PendingOp)
Accum = longCount(Accum,Readout,PendingOp);
else
Accum = Readout;
FKeyPad.ReadOut.value = Accum;
PendingOp = Op;
FKeyPad.ReadOut.focus();
FKeyPad.ReadOut.select();
function useFun (st)
switch(st)
case "sin":
FKeyPad.ReadOut.value=Math.sin(FKeyPad.ReadOut.value);
FlagNewNum=true;
break;
case "cos":
FKeyPad.ReadOut.value=Math.cos(FKeyPad.ReadOut.value);
FlagNewNum=true;
break;
case "asin":
FKeyPad.ReadOut.value=Math.asin(FKeyPad.ReadOut.value);
FlagNewNum=true;
break;
case "acos":
FKeyPad.ReadOut.value=Math.acos(FKeyPad.ReadOut.value);
FlagNewNum=true;
break;
case "tan":
FKeyPad.ReadOut.value=Math.tan(FKeyPad.ReadOut.value);
FlagNewNum=true;
break;
case "atan":
FKeyPad.ReadOut.value=Math.atan(FKeyPad.ReadOut.value);
FlagNewNum=true;
break;
case "log":
FKeyPad.ReadOut.value=Math.log(FKeyPad.ReadOut.value);
FlagNewNum=true;
break;
case "exp":
FKeyPad.ReadOut.value=Math.exp(FKeyPad.ReadOut.value);
FlagNewNum=true;
break;
case "sqrt":
FKeyPad.ReadOut.value=Math.sqrt(FKeyPad.ReadOut.value);
FlagNewNum=true;
break;
case "1/x":
FKeyPad.ReadOut.value=1/FKeyPad.ReadOut.value;
FlagNewNum=true;
break;
case "x^2":
FKeyPad.ReadOut.value=parseFloat(FKeyPad.ReadOut.value)*parseFloat(FKeyPad.ReadOut.value);
FlagNewNum=true;
break;
case "x^3":
FKeyPad.ReadOut.value=parseFloat(FKeyPad.ReadOut.value)*parseFloat(FKeyPad.ReadOut.value)*parseFloat(FKeyPad.ReadOut.value);
FlagNewNum=true;
break;
function hexchange ()
var hex,dec;
dec = parseFloat(FKeyPad.ReadOut.value);
hex = dec.toString(16);
window.alert("该十进制数转成十六进制数为："+ hex);
function octchange ()
var oct,dec;
dec = parseFloat(FKeyPad.ReadOut.value);
oct = dec.toString(8);
window.alert("该十进制数转成八进制数为："+ oct);
function binchange ()
var bin,dec;
dec = parseFloat(FKeyPad.ReadOut.value);
bin = dec.toString(2);
window.alert("该十进制数转成二进制数为："+ bin);
function ni ()
var y,k=1;
y=parseFloat(FKeyPad.ReadOut.value);
for(var x=1;x<=y;x++)
k=k*x;
FKeyPad.ReadOut.value=k;
function Decimal ()
var curReadOut = FKeyPad.ReadOut.value;
if (FlagNewNum)
curReadOut = "0.";
FlagNewNum = false;
else
if (curReadOut.indexOf(".") == -1)
curReadOut += ".";
FKeyPad.ReadOut.value = curReadOut;
function ClearEntry ()
FKeyPad.ReadOut.value = "0";
FlagNewNum = true;
function Clear ()
Accum = "0";
PendingOp = "";
ClearEntry();
function Neg ()
window.alert(FKeyPad.ReadOut.value);
FKeyPad.ReadOut.value = longCount(FKeyPad.ReadOut.value,"-1","*");
function goReturn()
top.returnValue = FKeyPad.ReadOut.value;
self.close();
function CheckOut()
var keyCode = window.event.keyCode;
if (keyCode>=48 && keyCode<=57)
if (FlagNewNum)
FKeyPad.ReadOut.value = "";
FlagNewNum = false;
return true;
else if (keyCode==43 || keyCode==45 || keyCode==42 || keyCode==47 || keyCode==61)
Operation(String.fromCharCode(keyCode));
else if (keyCode==46)
if (FKeyPad.ReadOut.value.indexOf(".") == -1)
return true;
else if (keyCode==27) goReturn();
window.event.returnValue = false;
return false;
// End -->
</SCRIPT>
</body>
</html>
参考资料：javascript
参考技术A <html xmlns="http://www.w3.org/1999/xhtml" ><head runat="server">
<title>无标题页</title>
<script type="text/javascript">
function cc(x)
x.result.value=eval(x.expression.value)
</script>
<input type="text" name="expression" size="20" id="tt1"/>
<br />
<input type="button" id="b1" value="请单击这里计算表达式" onclick="cc(form1)" disabled="disabled"/>
</head>
<body>
<h2>一个简单的计算器</h2>
<form id="form1" runat="server">
请输入表达式：
<input type="text" name="expression" size="20" id="tt1"/>
<br />
<input type="button" id="b1" value="请单击这里计算表达式" onclick="cc(form1)" disabled="disabled"/>
<br />
表达式的结果是：
<input type="text" name="result" size="10" id="tt2" />
</form>
</body>
</html> 参考技术B <HTML>
<HEAD>
<TITLE>JavaScript计算器</TITLE>
<style type="text/css">
p font-size: 12pt
.red color: red;width:34
.redlcolor:red;width:51
.blue color: blue;width:34
</style>
<SCRIPT LANGUAGE="JavaScript" src="calculate.js"></script>
</HEAD>
<BODY>
<center>
<form name="calculator">
<table bgcolor="#aaaaaa" width="230">
<tr><td>
<table bgcolor="#cccccc" border="1">
<tr><td>
<table border=0 cellpadding="0">
<tr><td bgcolor="#000080"></td></tr>
<tr><td>
<table width="100%" border="0">
<tr><td colspan="6"><input type="text" readOnly name="answer" style="text-align:right" size="30" maxlength="30" value="0."></td></tr>
<tr><td colspan="6">
<table border="0" cellpadding="0">
<tr><td>
<input type="text" name="mem" size="3" maxlength="3" style="text-align:center" readOnly style="background:menu"> <input type="button" name="backspace" class="redl" value="退格" tok="\b" onClick="this.form.answer.value = oController.addNumber(this.tok);"> <input type="button" name="CE" class="redl" tok="CE" value="CE" onClick="oController.cleanError();this.form.answer.value = oController.doFun(this.tok)"> <input type="button" name="C" class="redl" tok="CE" value="C" onClick="this.form.answer.value = oController.doFun(this.tok)">
</td></tr>
</table>
</td></tr>
<tr><td><input type="button" name="MC" class="red" value=" MC " tok="MC" onClick="this.form.answer.value = oController.doFun(this.tok);this.form.mem.value='';"></td>
<td><input type="button" name="calc7" class="blue" value=" 7 " tok="7" onClick="this.form.answer.value = oController.addNumber(this.tok)"></td>
<td><input type="button" name="calc8" class="blue" value=" 8 " tok="8" onClick="this.form.answer.value = oController.addNumber(this.tok)"></td>
<td><input type="button" name="calc9" class="blue" value=" 9 " tok="9" onClick="this.form.answer.value = oController.addNumber(this.tok)"></td>
<td><input type="button" name="divide" class="red" value=" / " tok="/" onClick="this.form.answer.value = oController.addOper(this.tok)"></td>
<td><input type="button" name="sqrt" class="blue" value="sqrt" tok="sqrt" onClick="this.form.answer.value = oController.doFun(this.tok)"></td></tr>
<tr><td><input type="button" name="MR" class="red" value=" MR " tok="MR" onClick="this.form.answer.value = oController.doFun(this.tok);"></td>
<td><input type="button" name="calc4" class="blue" value=" 4 " tok="4" onClick="this.form.answer.value = oController.addNumber(this.tok)"></td>
<td><input type="button" name="calc5" class="blue" value=" 5 " tok="5" onClick="this.form.answer.value = oController.addNumber(this.tok)"></td>
<td><input type="button" name="calc6" class="blue" value=" 6 " tok="6" onClick="this.form.answer.value = oController.addNumber(this.tok)"></td>
<td><input type="button" name="multiply" class="red" value=" * " tok="*" onClick="this.form.answer.value = oController.addOper(this.tok)"></td>
<td><input type="button" name="percent" class="blue" value=" % " tok="%" onClick="this.form.answer.value = oController.doFun(this.tok)"></td></tr>
<tr><td><input type="button" name="MS" class="red" value=" MS " tok="MS" onClick="this.form.answer.value = oController.doFun(this.tok);this.form.mem.value='M';"></td>
<td><input type="button" name="calc1" class="blue" value=" 1 " tok="1" onClick="this.form.answer.value = oController.addNumber(this.tok)"></td>
<td><input type="button" name="calc2" class="blue" value=" 2 " tok="2" onClick="this.form.answer.value = oController.addNumber(this.tok)"></td>
<td><input type="button" name="calc3" class="blue" value=" 3 " tok="3" onClick="this.form.answer.value = oController.addNumber(this.tok)"></td>
<td><input type="button" name="minus" class="red" value=" - " tok="-" onClick="this.form.answer.value = oController.addOper(this.tok)"></td>
<td><input type="button" name="recip" class="blue" value="1/x " tok="1/x" onClick="this.form.answer.value = oController.doFun(this.tok)"></td></tr>
<tr><td><input type="button" name="Mplus" class="red" value=" M+ " tok="M+" onClick="this.form.answer.value = oController.doFun(this.tok);this.form.mem.value='M';"></td>
<td><input type="button" name="calc0" class="blue" value=" 0 " tok="0" onClick="this.form.answer.value = oController.addNumber(this.tok)"></td>
<td><input type="button" name="negate" class="blue" value="+/- " tok="+/-" onClick="this.form.answer.value = oController.doFun(this.tok)"></td>
<td><input type="button" name="dot" class="blue" value=" . " tok="." onClick="this.form.answer.value = oController.addNumber(this.tok)"></td>
<td><input type="button" name="plus" class="red" value=" + " tok="+" onClick="this.form.answer.value = oController.addOper(this.tok)"></td>
<td><input type="button" name="equal" class="red" value=" = " tok="=" onClick="this.form.answer.value = oController.addOper(this.tok)"></td>
</tr>
</table>
</td></tr>
</table>
</td></tr>
</table>
</td></tr>
</table>
</form>
</center>
</BODY>
</HTML>
calculate.js
(function()
//这里是定义一个控制器，用来对外开放计算接口和拦截计算中出现的异常
oController =
addNumber : function(tok)if(errorState()) return errorResult(); else return addNumber(tok),
addOper : function(tok)if(errorState()) return errorResult(); else return addOper(tok),
doFun : function(tok)if(errorState()) return errorResult(); else return doFun(tok),
cleanError : cleanError
//用来保存记忆的变量
var memery = 0;
//这是符号对应的计算规则，这里采用一个闭包的对照表来处理
var opMap =
"+":function(a,b)return b + a, //处理加法运算的闭包
"-":function(a,b)return b - a, //处理减法运算的闭包
"*":function(a,b)return b * a, //处理乘法运算的闭包
"/":function(a,b)return b / a, //处理除法运算的闭包
"=":function(a,b)return a, //处理最终结果
"C":init, //清零
"CE":init, //清零
"sqrt":function(a)return Math.sqrt(a), //计算开方
"1/x":function(a)return 1/a, //计算倒数
"%":function(a)return a/100, //求余数
"+/-":function(a)return -a, //正负号
"MS":function(a)memery = a; return a, //记忆
"M+":function(a)memery += a; return a, //累加记忆
"MR":function(a)return memery, //从记忆中读取
"MC":function(a)memery = 0; return a //清除记忆
//用来存储数值、操作符和输入缓存的数据结构
var oMemery =
numStack : [], //存储数值
operStack : [], //存储字符串
inBuffer : "" //输入显示缓存
//检测计算中出现的数字异常，若有，返回给控制器进行处理
function errorState()
with(oMemery)
var n = numStack[numStack.length - 1];
return n == Infinity || isNaN(n);
//若出现异常，这个函数提供出现异常时的数值结果（数值堆栈顶的值）
function errorResult()
with(oMemery)
return formatBuff(numStack[numStack.length - 1]);
//清除异常并从错误中恢复
function cleanError()
with(oMemery)
numStack[numStack.length - 1] = 0;
function init() //初始化
with(oMemery)
numStack.length = 0; //清空数值堆栈
operStack.length = 0; //清空操作符堆栈
numStack.push(0); //在数值堆栈中推入一个0作为栈顶
inBuffer = ""; //清空输入缓存
return inBuffer; //将清空后的缓存值（实际上是空字符串''）返回
function doOper() //计算表达式
with(oMemery)
if(operStack.length) //如果运算符堆栈中有值
try
//取得栈顶运算符对应的操作方法
var op = opMap[operStack.pop()];
var args = [];
//该方法需要提供几个操作数，可以通过检查op.length得到
for(var i = 0; i < op.length; i++)
//从数值堆栈中依次取相应的操作数进行处理
args.push(numStack.pop());
//在这里实际进行计算，并把计算结果重新压入堆栈
numStack.push(op.apply(this, args));
catch(ex)
alert(ex.message);
return numStack[numStack.length - 1];
//格式化显示的数值，主要是为了符合计算器的习惯，比如0显示成0.（带小数点）
function formatBuff(buf)
if(buf == "")
return "0.";
else
buf = parseFloat(buf);
return /\./.test(buf) ? buf : buf + ".";
function addNumber(tok) //输入数值
with(oMemery)
try
var token;
if(tok == "\b") //如果输入的是一个退格
token = inBuffer.slice(0,-1); //那么把缓存中的内容去掉一个
else
token = inBuffer + tok.toString(); //否则接受新输入的数字
//如果数值的第一位是小数点，显示的时候要补一个0
if(token.slice(0,1) == ".") token = 0 + token;
//判断输入接收后的结果是否满足数值的格式
if(/^([\d]+(\.)?[\d]*)?$/.test(token))
inBuffer = token; //如果满足，则确认接受，写入缓存
return formatBuff(inBuffer);
catch(ex)
alert(ex.message);
function addOper(tok) //输入运算符
with(oMemery)
try
//如果缓存中有数值，将它推入数值堆栈
if(inBuffer != "")
numStack.push(parseFloat(inBuffer));
//否则从操作符堆栈中将前一个输入的操作符弹出用当前操作符替代
else
operStack.pop();
var ret = doOper(); //计算表达式
operStack.push(tok); //将新输入的运算符推入堆栈
inBuffer = ""; //清空输入缓存
return formatBuff(ret);
catch(ex)
alert(ex.message);
function doFun(tok) //处理函数
with(oMemery)
try
//假如是一些函数如sqrt
var fun = opMap[tok];
//如果输入缓存无内容
if(inBuffer == "")
inBuffer = numStack.pop(); //从数值堆栈中取数
else
operStack.push(tok); //否则将函数推入操作符堆栈
//计算函数调用结果并放入数值堆栈
numStack.push(fun(parseFloat(inBuffer)));
inBuffer = ""; //清空缓存
return formatBuff(numStack[numStack.length - 1]);
catch(ex)
alert(ex.message);
init(); //这里执行前面定义的初始化函数
)(); 参考技术C 继续做梦吧
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