From 9daad59fa2578dcc9603833b0a9a22b93d362b5e Mon Sep 17 00:00:00 2001 From: MDN Date: Fri, 16 Apr 2021 00:10:51 +0000 Subject: [CRON] sync translated content --- .../api/parentnode/firstelementchild/index.html | 96 ++++++++++++++++++++++ .../web/api/parentnode/lastelementchild/index.html | 94 +++++++++++++++++++++ 2 files changed, 190 insertions(+) create mode 100644 files/zh-cn/orphaned/web/api/parentnode/firstelementchild/index.html create mode 100644 files/zh-cn/orphaned/web/api/parentnode/lastelementchild/index.html (limited to 'files/zh-cn/orphaned/web') diff --git a/files/zh-cn/orphaned/web/api/parentnode/firstelementchild/index.html b/files/zh-cn/orphaned/web/api/parentnode/firstelementchild/index.html new file mode 100644 index 0000000000..8e658b4adc --- /dev/null +++ b/files/zh-cn/orphaned/web/api/parentnode/firstelementchild/index.html @@ -0,0 +1,96 @@ +--- +title: Element.firstElementChild +slug: orphaned/Web/API/ParentNode/firstElementChild +translation_of: Web/API/ParentNode/firstElementChild +original_slug: Web/API/ParentNode/firstElementChild +--- +

{{ APIRef("DOM") }}

+ +

ParentNode.firstElementChild 只读属性，返回对象的第一个子 {{domxref("元素")}}, 如果没有子元素，则为null。

+ +
+

他的属性最初是在{{domxref("element遍历")}}纯接口中定义的。由于这个接口包含两组不同的属性，一个针对具有子元素的{{domxref("Node")}}，一个针对子元素的属性，因此它们被移动到两个单独的纯接口中，{{domxref("ParentNode")}}和{{domxref("ChildNode")}}。在本例中，firstElementChild移动到{{domxref("ParentNode")}}。这是一个相当技术性的更改，不应该影响兼容性。

+
+ +

语法

+ +
var element = node.firstElementChild;
+
+ +

例子

+ +
<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>
+
+ +

适用于 IE8、IE9 和 Safari 的 Polyfill

+ +
// Overwrites native 'firstElementChild' prototype.
+// Adds Document & DocumentFragment support for IE9 & Safari.
+// Returns array instead of HTMLCollection.
+;(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

+ + + + + + + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('DOM WHATWG', '#dom-parentnode-firstelementchild', 'ParentNode.firstElementChild')}}{{Spec2('DOM WHATWG')}}Splitted the ElementTraversalinterface in {{domxref("ChildNode")}} and ParentNode. This method is now defined on the latter.
+ The {{domxref("Document")}} and {{domxref("DocumentFragment")}} implemented the new interfaces.
{{SpecName('Element Traversal', '#attribute-firstElementChild', 'ElementTraversal.firstElementChild')}}{{Spec2('Element Traversal')}}Added its initial definition to theElementTraversal pure interface and use it on {{domxref("Element")}}.
+ +

浏览器兼容性

+ + + +

{{Compat("api.ParentNode.firstElementChild")}}

+ +

参见

+ +

Ed

+ + diff --git a/files/zh-cn/orphaned/web/api/parentnode/lastelementchild/index.html b/files/zh-cn/orphaned/web/api/parentnode/lastelementchild/index.html new file mode 100644 index 0000000000..566d3a1976 --- /dev/null +++ b/files/zh-cn/orphaned/web/api/parentnode/lastelementchild/index.html @@ -0,0 +1,94 @@ +--- +title: Element.lastElementChild +slug: orphaned/Web/API/ParentNode/lastElementChild +translation_of: Web/API/ParentNode/lastElementChild +original_slug: Web/API/ParentNode/lastElementChild +--- +

{{ APIRef("DOM") }}

+ +

只读属性 ParentNode.lastElementChild 返回对象的最后一个子{{domxref("Element", "元素")}}，如果没有子元素，则返回 null。

+ +
+

This property was initially defined in the {{domxref("ElementTraversal")}} pure interface. As this interface contained two distinct set of properties, one aimed at {{domxref("Node")}} that have children, one at those that are children, they have been moved into two separate pure interfaces, {{domxref("ParentNode")}} and {{domxref("ChildNode")}}. In this case, lastElementChild moved to {{domxref("ParentNode")}}. This is a fairly technical change that shouldn't affect compatibility.

+
+ +

语法

+ +
var element = node.lastElementChild;
+ +

例子

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

适用于 IE8、IE9 和 Safari 的 Polyfill

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

规范

+ + + + + + + + + + + + + + + + + + + +
规范状态备注
{{SpecName('DOM WHATWG', '#dom-parentnode-lastelementchild', 'ParentNode.lastElementChild')}}{{Spec2('DOM WHATWG')}}Splitted the ElementTraversal interface in {{domxref("ChildNode")}} and ParentNode. This method is now defined on the latter.
+ The {{domxref("Document")}} and {{domxref("DocumentFragment")}} implemented the new interfaces.
{{SpecName('Element Traversal', '#attribute-lastElementChild', 'ElementTraversal.lastElementChild')}}{{Spec2('Element Traversal')}}Added its initial definition to the ElementTraversal pure interface and use it on {{domxref("Element")}}.
+ +

浏览器兼容性

+ + + +

{{Compat("api.ParentNode.lastElementChild")}}

+ +

参见

+ + -- cgit v1.2.3-54-g00ecf