HTMLSelectElement.selectedIndex
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
HTMLSelectElement.selectedIndex
是一个长整型数,它反映了被选中的第一个 <option>
元素的索引值。值为 -1 时表明没有元素被选中。
值
一个数字。
示例
HTML
html
<p id="p">selectedIndex: 0</p>
<select id="select">
<option selected>Option A</option>
<option>Option B</option>
<option>Option C</option>
<option>Option D</option>
<option>Option E</option>
</select>
JavaScript
js
var selectElem = document.getElementById("select");
var pElem = document.getElementById("p");
// 当有新的<option>元素被选中时
selectElem.addEventListener("change", function () {
var index = selectElem.selectedIndex;
// 把 index 数据添加到 p 元素中
pElem.innerHTML = "selectedIndex: " + index;
});
规范
Specification |
---|
HTML # dom-select-selectedindex-dev |
浏览器兼容性
Report problems with this compatibility data on GitHubdesktop | mobile | |||||||||||
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selectedIndex |
Legend
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- Full support
- Full support
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