js:计算器 

<body>

<form >
    <input type="test"  name="num1">
   <input type="text" name="num2">
  <br>
  <input type="button" value="+" onclick="operate('+')"> 
   <input type="button" value="-" onclick="operate('-')">
  <input type="button" value="*" onclick="operate('*')">
  <input type="button" value="/" onclick="operate('/')">
  <br>
    <input type="text" name="result">
</form>

</body>

<script type="text/javascript">
   
   function operate(op){
       var n1 = document.forms[0].num1.value;
       var n2 = document.forms[0].num2.value;
       var end = document.forms[0].result;
       
       if(op=="+")
           end.value = parseFloat(n1)+parseFloat(n2);
       
       if(op=="-")
           end.value = parseFloat(n1)-parseFloat(n2);
      
       if(op=="*")
           end.value =parseFloat(n1)*parseFloat(n2);
      
       if(op=="/")
           end.value = parseFloat(n1/n2);
 
   }
   
   
</script>

注:知识点  document.forms[0].name.param

parseFloat(value)   //将输入的string转换为float

posted @ 2016-08-19 10:44  乱世_独自美  阅读(129)  评论(0)    收藏  举报