HTML DOM id 属性
JavaScript基础 2022-06-08 17:07:23小码哥的IT人生shichen
HTML DOM id 属性
定义和用法
id 属性可设置或返回下拉列表中选项的 id。
语法
optionObject.id=id实例
下面的例子可返回下拉列表中所选选项的 id：
<html>
<head>
<script type="text/javascript">
function alertOptionId()
{
var x=document.getElementById("mySelect").selectedIndex;
alert(document.getElementsByTagName("option")[x].id);
}
</script>
</head>
<body>
<form>
Select your favorite fruit:
<select id="mySelect">
<option id="apple">Apple</option>
<option id="orange">Orange</option>
<option id="pineapple">Pineapple</option>
<option id="banana">Banana</option>
</select>
<br /><br />
<input type="button" onclick="alertOptionId()" value="Alert id">
</form>
</body>
</html>TIY
完整实例【取得下拉列表中所选选项的 id】：
<html>
<head>
<script type="text/javascript">
function alertOptionId()
{
var x=document.getElementById("mySelect").selectedIndex;
alert(document.getElementsByTagName("option")[x].id);
}
</script>
</head>
<body>
<form>
Select your favorite fruit:
<select id="mySelect">
<option id="apple">Apple</option>
<option id="orange">Orange</option>
<option id="pineapple">Pineapple</option>
<option id="banana">Banana</option>
</select>
<br /><br />
<input type="button" onclick="alertOptionId()" value="Alert id">
</form>
</body>
</html>
可以使用本站在线JavaScript测试工具测试上述代码运行效果：http://www.phpcodeweb.com/runjs.html
