3回答

• 

  慕神5827342

  2017-01-18 20:20:26

  楼上，为什么startCount后面不用加（）

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• 

  王延

  2016-11-21 10:13:05

    var num=0;
    function startCount() {
      document.getElementById('count').value=num;
      num=num+1;
      setTimeout("startCount()",1000);
    }
    window.onload=startCount;

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• 

  慕容5538410

  2016-11-13 16:32:05

   
    <script type="text/javascript">
     function count(){
      var oTxt1 = document.getElementById("txt1").value;
      var oTxt2 = document.getElementById("txt2").value;
      var oSlt = document.getElementById("select").value;
      var result = "";
      switch(oSlt) {
          case "+":
              result = parseFloat(oTxt1) + parseFloat(oTxt2);
              break;
          case "-":
              result = parseFloat(oTxt1) - parseFloat(oTxt2);
              break;
          case "*":
              result = parseFloat(oTxt1) * parseFloat(oTxt2);
              break;
          default:
              result = parseFloat(oTxt1) / parseFloat(oTxt2);
      }
      document.getElementById("fruit").value = result;
      
     }
    </script>
   
  

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