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javascript计算器
摘要: javascript计算器
<head>
</head>
<body bgcolor="#ffffff" onload="FKeyPad.ReadOut.focus();FKeyPad.ReadOut.select();">
<form name="Keypad" action="">
<table align="center">
<table align="center" border=2 width=50 height=60 cellpadding=1 cellspacing=5>
<tr>
<td colspan=3 align=middle><input name="ReadOut" type="Text" onkeypress="CheckOut()" size=24 value="0" width=100%></td>
<td></td>
<td><input name="btnClear" type="Button" value=" C " onclick="Clear()"></td>
<td><input name="btnClearEntry" type="Button" value=" CE " onclick="ClearEntry()"></td>
</tr>
<tr>
<td><input name="btnSeven" type="Button" value=" 7 " onclick="NumPressed(7)"></td>
<td><input name="btnEight" type="Button" value=" 8 " onclick="NumPressed(8)"></td>
<td><input name="btnNine" type="Button" value=" 9 " onclick="NumPressed(9)"></td>
<td></td>
<td><input name="btnNeg" type="Button" value=" +/- " onclick="Neg()"></td>
<td><input name="btnPercent" type="Button" value=" % " onclick="Percent()"></td>
</tr>
<tr>
<td><input name="btnFour" type="Button" value=" 4 " onclick="NumPressed(4)"></td>
<td><input name="btnFive" type="Button" value=" 5 " onclick="NumPressed(5)"></td>
<td><input name="btnSix" type="Button" value=" 6 " onclick="NumPressed(6)"></td>
<td></td>
<td align=middle><input name="btnPlus" type="Button" value=" + " onclick="Operation('+')"> </td>
<td align=middle><input name="btnMinus" type="Button" value=" - " onclick="Operation('-')"></td>
</tr>
<tr>
<td><input name="btnOne" type="Button" value=" 1 " onclick="NumPressed(1)"></td>
<td><input name="btnTwo" type="Button" value=" 2 " onclick="NumPressed(2)"></td>
<td><input name="btnThree" type="Button" value=" 3 " onclick="NumPressed(3)"></td>
<td></td>
<td align=middle><input name="btnMultiply" type="Button" value=" * " onclick="Operation('*')"></td>
<td align=middle><input name="btnDivide" type="Button" value=" / " onclick="Operation('/')"></td>
</tr>
<tr>
<td><input name="btnZero" type="Button" value=" 0 " onclick="NumPressed(0)"></td>
<td><input name="btnDecimal" type="Button" value=" . " onclick="Decimal()"></td>
<td colspan=2></td>
<td><input name="btnEquals" type="Button" value=" = " onclick="Operation('=')"></td>
<td><input name="btnReturn" type="Button" value="返 回" onclick="goReturn()"></td>
</tr>
</table>
</table>
</form>
<script LANGUAGE="JavaScript">
//===============================================================================
//[描述] 浮点数精确计算
//[参数] str1 - 第一个数
// str2 - 第二个数
// type - 运算符
// precision - 小数位精度
//[调用方式] longCount(str1,str2,type,precision);
//[返回值] 计算结果
//===============================================================================
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
}else {
for (var i=0;i
}
}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);
}
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)
Accum = longCount(Accum,Readout,PendingOp);
else
Accum = Readout;
FKeyPad.ReadOut.value = Accum;
PendingOp = Op;
FKeyPad.ReadOut.focus();
FKeyPad.ReadOut.select();
}
}
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 () {
alert(FKeyPad.ReadOut.value);
FKeyPad.ReadOut.value = longCount(FKeyPad.ReadOut.value,"-1","*");
}
function Percent () {
FKeyPad.ReadOut.value = longCount(FKeyPad.ReadOut.value,Accum,"*");
FKeyPad.ReadOut.value = longCount(FKeyPad.ReadOut.value,100,"/");
}
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 = "";
//window.event.keyCode = null;
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==13) goReturn();
window.event.returnValue = false;
return false;
}
// End
</script>
</body>