ParentNode.firstElementChild

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句法
范例
Polyfill for IE8, IE9 and Safari
规范
浏览器兼容性
另请参阅
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ParentNode.firstElementChild read-only property returns the object's first child 元素 ，或 null if there are no child elements.

This property was initially defined in the ElementTraversal pure interface. As this interface contained two distinct set of properties, one aimed at 节点 that have children, one at those that are children, they have been moved into two separate pure interfaces, ParentNode and ChildNode 。在此情况下， firstElementChild moved to ParentNode . This is a fairly technical change that shouldn't affect compatibility.

句法

var element = node.firstElementChild;

范例

<ul id="foo">
  <li>First  (1)</li>
  <li>Second (2)</li>
  <li>Third  (3)</li>
</ul>
<script>
var foo = document.getElementById('foo');
// yields: First  (1)
console.log(foo.firstElementChild.textContent);
</script>

Polyfill for IE8, IE9 and Safari

// Overwrites native 'firstElementChild' prototype.
// Adds Document & DocumentFragment support for IE9 & Safari.
;(function(constructor) {
    if (constructor &&
        constructor.prototype &&
        constructor.prototype.firstElementChild == null) {
        Object.defineProperty(constructor.prototype, 'firstElementChild', {
            get: function() {
                var node, nodes = this.childNodes, i = 0;
                while (node = nodes[i++]) {
                    if (node.nodeType === 1) {
                        return node;
                    }
                }
                return null;
            }
        });
    }
})(window.Node || window.Element);

规范

规范	状态	注释
DOM The definition of 'ParentNode.firstElementChild' in that specification.	实时标准	Split the `ElementTraversal` interface in `ChildNode` and `ParentNode` . This method is now defined on the latter. `Document` and `DocumentFragment` implemented the new interfaces.
Element Traversal Specification The definition of 'ElementTraversal.firstElementChild' in that specification.	过时	Added its initial definition to the `ElementTraversal` pure interface and use it on `元素` .

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`firstElementChild`	Chrome 1	Edge 12	Firefox 3.5	IE 9	Opera 10	Safari 4	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
Support on `Document` and `DocumentFragment`	Chrome 29	Edge ≤79	Firefox 25	IE No	Opera 16	Safari No	WebView Android Yes	Chrome Android Yes	Firefox Android ?	Opera Android ?	Safari iOS No	Samsung Internet Android Yes

图例

完整支持
不支持
兼容性未知 ?
实验。期望将来行为有所改变。

另请参阅

NonDocumentTypeChildNode.nextElementSibling
ParentNode.lastElementChild
ParentNode and ChildNode pure interfaces.
Object types implementing this pure interface: Document , 元素 ，和 DocumentFragment .

元数据

最后修改： Sep 8, 2019

DOM (文档对象模型)
ParentNode
特性
1. childElementCount
2. children
3. firstElementChild
4. lastElementChild
方法
实现通过：
DOM 相关页面

在此页

句法

范例

Polyfill for IE8, IE9 and Safari

规范

浏览器兼容性

图例

另请参阅

相关话题