js网页版计算器的简单实现

复制代码 代码如下:

  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

  <html xmlns="http://www.w3.org/1999/xhtml">

  <head>

  <meta http-equiv="Content-Type" content="text/html; charset=gb2312" />

  <title>计算器</title>

  <script language="javascript" type="text/javascript">

  var clearFlag=false;

  function getNum(num){

  //alert(num);

  var objresult=document.getElementById("result");

  if(clearFlag){

  objresult.value="";

  clearFlag=false;

  }

  //alert(objresult);

  objresult.value+=num;

  }

  function getResult(){

  var objresult=document.getElementById("result");

  objresult.value=objresult.value+"="+eval(objresult.value);

  clearFlag=true;

  }

  </script>

  </head>

  <body>

  <table width="200" border="1" cellpadding="2">

  <tr>

  <td colspan="4"><input type="text" name="result" id="result" size="33"></td>

  </tr>

  <tr>

  <td width="56"><input type="button" value="  1   " onclick="getNum(1)"></td>

  <td width="56"><input type="button" value="  2   " onclick="getNum(2)"></td>

  <td width="51"><input type="button" value="  3   " onclick="getNum(3)"></td>

  <td width="58"><input type="button" value="  +   " onclick="getNum('+')"></td>

  </tr>

  <tr>

  <td><input type="button" value="  4   " onclick="getNum(4)"></td>

  <td><input type="button" value="  5   " onclick="getNum(5)"></td>

  <td><input type="button" value="  6   " onclick="getNum(6)"></td>

  <td><input type="button" value="  -   " onclick="getNum('-')"></td>

  </tr>

  <tr>

  <td><input type="button" value="  7   " onclick="getNum(7)"></td>

  <td><input type="button" value="  8   " onclick="getNum(8)"></td>

  <td><input type="button" value="  9   " onclick="getNum(9)"></td>

  <td><input type="button" value="  *   " onclick="getNum('*')"></td>

  </tr>

  <tr>

  <td><input type="button" value="  0   " onclick="getNum(0)"></td>

  <td><input type="button" value="  .   " onclick="getNum('.')"></td>

  <td><input type="button" value="  =   " onclick="getResult()"></td>

  <td><input type="button" value="  /   " onclick="getNum('/')"></td>

  </tr>

  </table>

  </body>

  </html>