js-计算器大家看下 - 编程论坛

#2

poyexyp2010-06-28 11:04

1.undifined是因为第一次使用addnum（）的时候expression变量只声明而未赋值。所以expression+=cv;就会变成undifined+输入值，所以可以给全局变量声明的时候赋空值就不会有这个问题。
var expression="";
2.注释掉的代码块里问题比较多：两个if条件里面的判断（==）都写成赋值（=）了；两个if的功能有点重；判断放在addnum里面不如放在计算结果里面；

#3

lubo9992010-06-28 16:26

路过，看到这个代码不是很简洁

#4

gulimeksoft2010-08-06 17:42

程序代码：

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<HTML>
<HEAD>
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
<META name="GENERATOR" content="IBM Software Development Platform">
<META http-equiv="Content-Style-Type" content="text/css">
<LINK href="theme/Master.css" rel="stylesheet" type="text/css">
<TITLE>test5.html</TITLE>
</HEAD>
<BODY>
<P>Place content here.</P>
<style type="text/css">

</style>
<script language="javascript">

var expression="";
function numAdd(cv){

/*

var num = document.form1.text1.value;
if (cv="+" || cv="-" || cv="*" || cv="/" )
      {
       document.form1.text1.value="";
       }
if (num.charAt(0)="" || num.charAt(0)="+" || num.charAt(0)="-" || num.charAt(0)="*" || num.charAt(0)="/" )
      {
       alert("这样无法计算");
       expression="";
       }

*/
var e=expression.length-1;
var d=expression.charAt(e);
if(cv=="0"){if(d=="/"){alert("0不能作除数");return false}}
if(cv=="+"||cv=="*"||cv=="-"||cv=="/"){
if(d=="+"||d=="*"||d=="-"||d=="/"){return false;}
if(expression!=""){expression=eval(expression);}}
expression+=cv;
if(expression=="*"||expression=="/"){expression="";}
document.form1.text1.value=expression;

}

function compute(){
var e=expression.length-1;
var d=expression.charAt(e);
if(d=="+"||d=="*"||d=="-"||d=="/"){return false;}
document.form1.text1.value=eval(expression);
expression=document.form1.text1.value;
}

function crt(){
expression="";
document.form1.text1.value="";
}

</script>

<form name="form1">
    <table width="177" height="150" border="1"  align="center" cellpadding="0" style="border:1px solid #9900CC ">
  <tr>
    <td colspan="4"  align="center"> <span class="STYLE1">计算器</span></td>
    </tr>
  <tr>
    <td colspan="4" align="center"><input type="text" name="text1" height="20"  value=""></td>
   </tr>
  <tr>
    <td width="40" align="center">
      <input type="button" name="b1" value=" 1 " onClick="numAdd('1');"></td>
    <td width="40" align="center"> <input type="button" name="b2" value=" 2 " onClick="numAdd('2');"></td>
    <td width="40" align="center"> <input type="button" name="b3" value=" 3 " onClick="numAdd('3');"></td>
    <td width="40" align="center"> <input type="button" name="bb" value=" / " onClick="numAdd('/');"></td>
  </tr>
  <tr>
    <td width="40" align="center"> <input type="button" name="b4" value=" 4 " onClick="numAdd('4');"></td>
    <td width="40" align="center"> <input type="button" name="b5" value=" 5 " onClick="numAdd('5');"></td>
    <td width="40" align="center"> <input type="button" name="b6" value=" 6 " onClick="numAdd('6');"></td>
    <td width="40" align="center"> <input type="button" name="bc" value=" * " onClick="numAdd('*');"></td>
  </tr>
  <tr>
    <td width="40" align="center"> <input type="button" name="b7" value=" 7 " onClick="numAdd('7');"></td>
    <td width="40" align="center"> <input type="button" name="b8" value=" 8 " onClick="numAdd('8');"></td>
    <td width="40" align="center"> <input type="button" name="b9" value=" 9 " onClick="numAdd('9');"></td>
    <td width="40" align="center"> <input type="button" name="bd" value=" - " onClick="numAdd('-');"></td>
  </tr>
  <tr>
    <td width="40" align="center"> <input type="reset" name="be" value=" CE" onClick="crt();"></td>
    <td align="center"><input type="button" name="bo" value=" 0 " onClick="numAdd('0');"></td>
    <td align="center"><input type="button" name="ba" value=" = " onClick="compute();"></td>
    <td width="40" align="center"> <input type="button" name="badd" value=" + " onClick="numAdd('+');"></td>
  </tr>
</table>

</form>
</BODY>
</HTML>

你的程序蛮不错的，我给你改了一下，不好意思

#5

ztslove2010-08-06 20:04

回复 4楼 gulimeksoft

呵呵这个发了很长时间了谢谢看了你写的很不错收藏了交割朋友吧 QQ：396362666

#6

檐語2010-11-27 23:43

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> 简单计算器</TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<script language="JavaScript">

      var m=0;     //是第一操作数

      function SetExp(str){
      if(m==1)   //根据m值判定结果是否为第一操作数
      {   document.Nform.result.value="";
           m=0;
      }
      else(m==0)
      {  document.Nform.result.value+=str;
      }
      }

      function Cal(result){
      var str=document.Nform.result.value;
      document.Nform.result.value=eval(str);
      m=1;
      }
      function Clear(){
      document.Nform.result.value="";
      }

</script>
</HEAD>

<BODY>
<center>
<h2></h2>
<form name=Nform method=get>
<table border="1" bordercolor="#003300">
<tr>
     <td colspan="3">
           <input type=text name="result">
     </td>
</tr>
<tr align="center">
     <td>
           <input type="button" value="1" onClick="SetExp('1')">
    </td>
     <td>
           <input type="button" value="2" onClick="SetExp('2')">
    </td>
     <td>
           <input type="button" value="3" onClick="SetExp('3')">
    </td>
</tr>
<tr align="center">
     <td>
           <input type="button" value="4" onClick="SetExp('4')">
    </td>
     <td>
           <input type="button" value="5" onClick="SetExp('5')">
    </td>
     <td>
           <input type="button" value="6" onClick="SetExp('6')">
    </td>
</tr>
<tr align="center">
     <td>
           <input type="button" value="7" onClick="SetExp('7')">
    </td>
     <td>
           <input type="button" value="8" onClick="SetExp('8')">
    </td>
     <td>
           <input type="button" value="9" onClick="SetExp('9')">
    </td>
</tr>
<tr align="center">
     <td>
           <input type="button" value="0" onClick="SetExp('0')">
    </td>
     <td>
           <input type="button" value="." onClick="SetExp('.')">
    </td>
     <td>
           <input type="button" value="C" onClick="Clear()">
    </td>
</tr>
<tr align="center">
     <td>
           <input type="button" value="+" onClick="SetExp('+')">
    </td>
     <td>
           <input type="button" value="-" onClick="SetExp('-')">
    </td>
     <td>
           <input type="button" value="*" onClick="SetExp('*')">
    </td>
</tr>
<tr align="center">
     <td>
           <input type="button" value="/" onClick="SetExp('/')">
    </td>
     <td colspan="2">
           <input type="button" value="=" onClick="Cal()">
    </td>
    </tr>
</table>
</form>
</center>

</BODY>
</HTML>