沒結(jié)果的，幫忙看看，謝謝
<!DOCTYPE html>
<html>
?<head>
? <title> 事件</title> ?
? <script type="text/javascript">
?function count(){
? ? var txt1 ? = parseInt( document.getElementById('txt1').value);
var txt2 ? = parseInt( document.getElementById('txt2').value);
var select = document.getElementById('select').value;
var result = '';
switch (select)
{
case '+':
result = txt1 + txt2;
break;
case '-':
result = txt1 - txt2;
break;
case '*':
result = txt1 * txt2;
break;
case '/':
result = txt1 / txt2;
break; ?
}
?document.getElementById('fruit').value = result;
? ?}
? </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=' = ' /> <!--通過 = 按鈕來調(diào)用創(chuàng)建的函數(shù)，得到結(jié)果-->?
? ?<input type='text' id='fruit' /> ??
?</body>
</html>
2016-12-22
body里面注釋那里你得添加命令運(yùn)行函數(shù)啊 ?onclick="count()"