結果是NaN
<!DOCTYPE?html>
<html>
?<head>
??<title>?事件</title>??
??<script?type="text/javascript">
???function?count(){
????var?t1=document.getElementById("txt1").value;??
????//獲取第一個輸入框的值
????var?t2=document.getElementById("txt2").value;??
//獲取第二個輸入框的值
var?s=document.getElementById("select").value;??
//獲取選擇框的值
var?result;
switch(s){
???case?"+":
???????result=parseInt("t1")+parseInt("t2");
???????break;
???case?"-":
???????result=parseInt("t1")-parseInt("t2");
???????break;
???????case?"*":
???????????result=parseInt("t1")*parseInt("t2");
???????break;
???case?"/":
???????result=parseInt("t1")/parseInt("t2");
???????break;
}
//獲取通過下拉框來選擇的值來改變加減乘除的運算法則
document.getElementById("fruit").value=result;
????//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>請問我錯哪了，不管加減乘除結果都是NaN
2017-06-19
result=parseInt("t1")+parseInt("t2");???多了雙引號，下面3句也一樣 把雙引號去掉就可以 result=parseInt(t1)+parseInt(t2);