JavaScript小型计算器

昵称11236445 2012-12-03

展开全文

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www./TR/html4/loose.dtd">
<html>
<head>
<title> New Document </title>
<meta name="Generator" content="EditPlus">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
</head>

<body>
<center>
<legend><h1><b> <font size="楷体_GB2312" color="#9900ff" >我的小型计算器：</font></b></h1></legend>
<form name="Keypad" method="post" action="" >
    <table>
   <b>
   <table border=3 width=50 height=60 cellpadding=1 cellspacing=5 >

   <tr bgcolor="#cccccc">
       <td colspan=3 align=middle><input name="ReadOut" type="Text" size=24 value="0" width=100%></td>
       <td><input name="btnClear" type="Button" size=24 value="C" onclick="Clear()"></td>
       <td><input name="btnClearEntry" type="Button" size=24 value="CE" onclick="ClearEntry()">
       </td>
   </tr>
   <tr bgcolor="#cccccc">

       <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><input name="btnNeg" type="Button" value="+/-" onclick="Neg()"></td>
       <td><input name="btnPercent" type="Button" value="%" onclick="Percent()"></td>

   </tr>
   <tr bgcolor="#cccccc">

       <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 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 bgcolor="#cccccc">
       <td><input name="btnOne" type="Button" value="1" onclick="NumPressed(1)"></td>
       <td><input name="btnTow" type="Button" value="2" onclick="NumPressed(2)"></td>
       <td><input name="btnThree" type="Button" value="3" onclick="NumPressed(3)"></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 bgcolor="#cccccc">
       <td><input name="btnZero" type="button" value="0" onclick="NumPressed(0)"></td>
       <td><input name="btnDecimal" type="button" value="." onclick="Decimal()"></td>
      <td><input name="btnRetreat" type="button" value="<-" onclick="Retreat()"></td>
       <td></td>
       <td align = middle><input name="btnEquals" type="Button" value="=" onclick="Operation('=')"></td>

   </tr>
   </table>

   </b>
</form>
</center>
<script language="javascript">

var FKeyPad= document.Keypad;
var Accum = 0;
var NewNum = false;
var PendingOp="Op";//未定义的运算符 PendingOp
//数字键
function NumPressed(Num){

    if(NewNum){
      FKeyPad.ReadOut.value=Num;
      NewNum=false;
     }
   else{
      if(FKeyPad.ReadOut.value=="0")
          FKeyPad.ReadOut.value=Num;
      else
      FKeyPad.ReadOut.value+=Num;
   }
}
//运算符
function Operation(Op){
     var ReadOut=FKeyPad.ReadOut.value
     if(NewNum&&PendingOp!="="){
       FKeyPad.ReadOut.value=Op;
     }
    else{
      NewNum =true;
      if(PendingOp=='+'){
      Accum += parseFloat(ReadOut);}
      else if('-'==PendingOp){
      Accum -= parseFloat(ReadOut);}
      else if('*'==PendingOp){
      Accum *= parseFloat(ReadOut);}
      else if('/'==PendingOp){
      Accum /= parseFloat(ReadOut);}
   else
      Accum = parseFloat(ReadOut);
      FKeyPad.ReadOut.value=Accum;
      PendingOp=Op;

   }
}//小数计算 Decimal
function Decimal(){
     var ReadOut = FKeyPad.ReadOut.value;
     if(NewNum){
   ReadOut="0.";
   NewNum=false;
   }
     else{
      if(ReadOut.indexOf(".")==-1){
      ReadOut +=".";
      }
      FKeyPad.ReadOut.value=ReadOut;

    }
}
//清空
function ClearEntry(){
     FKeyPad.ReadOut.value="0";
     NewNum = true;
}
function Clear(){

     Accum = "";
    PendingOp="";
   ClearEntry();
}
//负数
function Neg(){
     FKeyPad.ReadOut.value=parseFloat(FKeyPad.ReadOut.value)*-1;
}
//百分数
function Percent(){
     FKeyPad.ReadOut.value=(parseFloat(FKeyPad.ReadOut.value)/100)*parseFloat(Accum);
}
//退格
function Retreat(){
    var Num = FKeyPad.ReadOut.value;

//    Num=(Num - Num.substring(FKeyPad.ReadOut.value.length-1))/10;

      Num = Num.substring(0,Num.length-1);

      FKeyPad.ReadOut.value=Num;
}
</script>

</body>
</html>