<!DOCTYPE?html>
<html>
?<head>
??<title>?事件</title>??
??<script?type="text/javascript">
???function?count(){
???????var?text1?=?document.getElementById("text1").value;
???????var?text2?=?document.getElementById("text2").value;
???????var?select?=?document.getElementById("select").value;
???????var?fruit='';
???????switch?(select){
???????????case?"+":
????????????fruit?=?text1?+?text2;
????????????break;
???????????case?"-":
????????????fruit?=?text1?-?text2;
????????????break;
????????????case?"*":
????????????fruit?=?text1?*?text2;
????????????break;
????????????case?"/":
????????????fruit?=?text1?/?text2;
????????????break;
????????????default;
???????}
????????document.getElementById("fruit").value?=?fruit;
???}
??</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>
2015-04-04
代碼有以下問題:
7、8的getElementById傳入的id錯了
default后面是冒號;
通過id獲得的值需要轉化成整型。
完整的代碼: