求問...錯在哪了啊,和同學代碼對了3遍了!然后自己寫還是不能!焦頭爛額了!
<!DOCTYPE html>
<html>
?<head>
? <title> 事件</title>?
? <script type="text/javascript">
?? function count(){
??? var oTxt1=document.getElementById("txt1").value;
??? var oTxt2=document.getElementById("txt2").value;
??? var oSel=document.getElementById("select").value;
??? var res="";
??? switch(oSel){
??????? case "+":
??????????? res=parseInt(oTxt1)+parseInt(oTxt2);
??????????? break;
??????? case "-":
??????????? res=parseInt(oTxt1)-parseInt(oTxt2);
??????????? break;
??????? case "*":
??????????? res=parseInt(oTxt1)*parseInt(oTxt2);
??????????? break;
??????? default:
??????????? res=parseInt(oTxt1)/parseInt(oTxt2);
??? }
??? document.getElementById("fruit")=res;
??? //獲取第一個輸入框的值
?//獲取第二個輸入框的值
?//獲取選擇框的值
?//獲取通過下拉框來選擇的值來改變加減乘除的運算法則
??? //設置結果輸入框的值
?? }
? </script>
?</head>
?<body>
?? <input type='text' id='txt1' />
?? <select id='select'>
??<option value='+'>+</option>
??<option value="-">-</option>
??<option value="*">*</option>
??<option value="/">/</option>
?? </select>
?? <input type='text' id='txt2' />
?? <input type='button' value=' = ' onclick="count()"/> <!--通過 = 按鈕來調用創建的函數，得到結果-->
?? <input type='text' id='fruit' />??
?</body>
</html>
2015-06-12
?document.getElementById("fruit")=res;
改為
?document.getElementById("fruit").value=res;