<!DOCTYPE?html>
<html>
?<head>
??<title>?事件</title>??
??<script?type="text/javascript">
???function?count(){
???????
????//獲取第一個輸入框的值
????var?txt1?=?document.getElementById("txt1").value;
????
????//獲取第二個輸入框的值
????var?txt2?=?document.getElementById("txt2").value;
//獲取選擇框的值
????var?select?=?document.getElementById("select").value;
//獲取通過下拉框來選擇的值來改變加減乘除的運算法則
????var?my?=?"?";
????//設置結果輸入框的值?
????switch(select){
????????case?"+":
????????my=txt1+txt2;
????????break;
????????
????????case?"-":
????????my=txt1-txt2;
????????break;
????????
????????case?"*":
????????my=txt1*txt2;
????????break;
????????
????????case?"/":
????????my=txt1/txt2;
????????break;
????}
????document.getElementById("fruit").value=my;
???}
??</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(chuàng)建的函數，得到結果-->?
???<input?type='text'?id='fruit'?/>???
?</body>
</html>
大神看下為什么加法不對 其他的卻對了。
菜鳥攻城獅i
2015-07-16 22:50:47
