<!DOCTYPE?html>????
<html>????
<head>????
<title>?new?document?</title>??????
<script?type="text/javascript">????
function?count(){????
var?txt1???=?parseInt(?document.getElementById('txt1').value);//鑾峰彇絎竴涓緭鍏ユ鐨勫€?????
var?txt2???=?parseInt(?document.getElementById('txt2').value);//鑾峰彇絎簩涓緭鍏ユ鐨勫€?????
var?select?=?document.getElementById('select').value;//鑾峰彇閫夋嫨妗嗙殑鍊?????
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='??=??'??onclick?=?"count()"?/>?????
<input?type='text'?id='fruit'?/>???????
</body>????
</html>第一個問題 想問一下 為什么var select = document.getElementById('select').value;一定要后面有.value;?代表什么意思？第二個問題我在w3c那個網站里面看了一下關于select這個標簽 沒有找到它有value這個屬性 請問是因為w3c并不是所有屬性都會羅列出來的關系嘛？謝謝！
selectObject.value這個屬性返回的是什么
Beckybei
2015-09-08 14:55:24
