定义和用法
- selectedIndex 返回的是下拉框当中被选中的索引下标
<html>
<head>
<script type="text/javascript">
function getIndex()
{
var x=document.getElementById("mySelect")
alert(x.selectedIndex)
}
</script>
</head>
<body>
<form>
Select your favorite fruit:
<select id="mySelect">
<option>Apple</option>
<option>Orange</option>
<option>Pineapple</option>
<option>Banana</option>
</select>
<br /><br />
<input type="button" onclick="getIndex()"
value="Alert index of selected option">
</form>
</body>
</html>
