path: root/files/zh-tw/web/api/element/index.html

---
title: Element
slug: Web/API/Element
tags:
  - API
  - DOM
  - DOM Reference
  - Element
  - NeedsTranslation
  - TopicStub
  - Élément(2)
translation_of: Web/API/Element
---
<p>{{ APIRef("DOM") }}</p>

<p><span class="seoSummary"><strong><code>Element</code></strong> 介面表示了一個在 {{domxref("Document")}} 中的物件，其描述了各類型元素的共同屬性與方法，<code>Element</code> 的子介面則定義了不同類型元素的具體行為並增加額外的功能。</span>例如 {{domxref("HTMLElement")}} 為所有 HTML 元素的基礎介面，而 {{domxref("SVGElement")}} 則是定義所有 SVG 元素的介面。</p>

<p>在 Web 領域之外，如 XUL 語言也能藉由 <code>XULElement</code> 介面來繼承 <code>Element</code>。</p>

<p>{{InheritanceDiagram}}</p>

<h2 id="Properties" name="Properties">屬性</h2>

<p><em>Inherits properties from its parent interface, {{domxref("Node")}}, and by extension that interface's parent, {{domxref("EventTarget")}}. It implements the properties of {{domxref("ParentNode")}}, {{domxref("ChildNode")}}, {{domxref("NonDocumentTypeChildNode")}}, </em>and {{domxref("Animatable")}}.</p>

<dl>
 <dt>{{ domxref("Element.assignedSlot")}} {{experimental_inline}} {{readOnlyInline}}</dt>
 <dd>Returns the {{domxref("HTMLSlotElement")}} interface associated with the element.</dd>
 <dt>{{ domxref("Element.attributes") }} {{readOnlyInline}}</dt>
 <dd>Returns a {{ domxref("NamedNodeMap") }} object containing the assigned attributes of the corresponding HTML element.</dd>
 <dt>{{ domxref("Element.classList") }} {{readOnlyInline}}</dt>
 <dd>Returns a {{ domxref("DOMTokenList") }} containing the list of class attributes.</dd>
 <dt>{{ domxref("Element.className") }}</dt>
 <dd>Is a {{domxref("DOMString")}} representing the class of the element.</dd>
 <dt>{{ domxref("Element.clientHeight") }} {{experimental_inline}} {{readOnlyInline}}</dt>
 <dd>Returns a {{jsxref("Number")}} representing the inner height of the element.</dd>
 <dt>{{ domxref("Element.clientLeft") }} {{experimental_inline}} {{readOnlyInline}}</dt>
 <dd>Returns a {{jsxref("Number")}} representing the width of the left border of the element.</dd>
 <dt>{{ domxref("Element.clientTop") }} {{experimental_inline}} {{readOnlyInline}}</dt>
 <dd>Returns a {{jsxref("Number")}} representing the width of the top border of the element.</dd>
 <dt>{{ domxref("Element.clientWidth") }} {{experimental_inline}} {{readOnlyInline}}</dt>
 <dd>Returns a {{jsxref("Number")}} representing the inner width of the element.</dd>
 <dt>{{domxref("Element.computedName")}} {{readOnlyInline}}</dt>
 <dd>Returns a {{domxref("DOMString")}} containing the label exposed to accessibility.</dd>
 <dt>{{domxref("Element.computedRole")}} {{readOnlyInline}}</dt>
 <dd>Returns a {{domxref("DOMString")}} containing the ARIA role that has been applied to a particular element.</dd>
 <dt>{{ domxref("Element.id") }}</dt>
 <dd>Is a {{domxref("DOMString")}} representing the id of the element.</dd>
 <dt>{{ domxref("Element.innerHTML") }}</dt>
 <dd>Is a {{domxref("DOMString")}} representing the markup of the element's content.</dd>
 <dt>{{ domxref("Element.localName") }} {{readOnlyInline}}</dt>
 <dd>A {{domxref("DOMString")}} representing the local part of the qualified name of the element.</dd>
 <dt>{{domxref("Element.namespaceURI")}} {{readonlyInline}}</dt>
 <dd>The namespace URI of the element, or <code>null</code> if it is no namespace.
 <div class="note">
 <p><strong>Note:</strong> In Firefox 3.5 and earlier, HTML elements are in no namespace. In later versions, HTML elements are in the <code><a class="linkification-ext external" href="http://www.w3.org/1999/xhtml" title="Linkification: http://www.w3.org/1999/xhtml">http://www.w3.org/1999/xhtml</a></code> namespace in both HTML and XML trees. {{ gecko_minversion_inline("1.9.2") }}</p>
 </div>
 </dd>
 <dt>{{ domxref("NonDocumentTypeChildNode.nextElementSibling") }} {{readOnlyInline}}</dt>
 <dd>Is a {{ domxref("Element") }}, the element immediately following the given one in the tree, or <code>null</code> if there's no sibling node.</dd>
 <dt>{{ domxref("Element.outerHTML") }} {{experimental_inline}}</dt>
 <dd>Is a {{domxref("DOMString")}} representing the markup of the element including its content. When used as a setter, replaces the element with nodes parsed from the given string.</dd>
 <dt>{{ domxref("Element.prefix") }} {{readOnlyInline}}</dt>
 <dd>A {{domxref("DOMString")}} representing the namespace prefix of the element, or <code>null</code> if no prefix is specified.</dd>
 <dt>{{ domxref("NonDocumentTypeChildNode.previousElementSibling") }} {{readOnlyInline}}</dt>
 <dd>Is a {{ domxref("Element") }}, the element immediately preceding the given one in the tree, or <code>null</code> if there is no sibling element.</dd>
 <dt>{{ domxref("Element.scrollHeight") }} {{experimental_inline}} {{readOnlyInline}}</dt>
 <dd>Returns a {{jsxref("Number")}} representing the scroll view height of an element.</dd>
 <dt>{{ domxref("Element.scrollLeft") }} {{experimental_inline}}</dt>
 <dd>Is a {{jsxref("Number")}} representing the left scroll offset of the element.</dd>
 <dt>{{ domxref("Element.scrollLeftMax") }} {{non-standard_inline}} {{readOnlyInline}}</dt>
 <dd>Returns a {{jsxref("Number")}} representing the maximum left scroll offset possible for the element.</dd>
 <dt>{{ domxref("Element.scrollTop") }} {{experimental_inline}}</dt>
 <dd>Is a {{jsxref("Number")}} representing the top scroll offset the an element.</dd>
 <dt>{{ domxref("Element.scrollTopMax") }} {{non-standard_inline}} {{readOnlyInline}}</dt>
 <dd>Returns a {{jsxref("Number")}} representing the maximum top scroll offset possible for the element.</dd>
 <dt>{{ domxref("Element.scrollWidth") }} {{experimental_inline}} {{readOnlyInline}}</dt>
 <dd>Returns a {{jsxref("Number")}} representing the scroll view width of the element.</dd>
 <dt>{{domxref("Element.shadowRoot") }} {{experimental_inline}} {{readOnlyInline}}</dt>
 <dd>Returns the youngest shadow root that is hosted by the element.</dd>
 <dt>{{domxref("Element.slot")}} {{experimental_inline}}</dt>
 <dd>Returns the name of the shadow DOM slot attatched to the element. A slot is a placeholder inside a web component that users can fill with their own markup.</dd>
 <dt>{{domxref("Element.tabStop")}} {{non-standard_inline}}</dt>
 <dd>Is a {{jsxref("Boolean")}} indicating if the element can receive input focus via the tab key.</dd>
 <dt>{{ domxref("Element.tagName") }} {{readOnlyInline}}</dt>
 <dd>Returns a {{domxref("String")}} with the name of the tag for the given element.</dd>
 <dt>{{ domxref("Element.undoManager")}} {{experimental_inline}} {{readOnlyInline}}</dt>
 <dd>Returns the {{domxref("UndoManager")}} associated with the element.</dd>
 <dt>{{ domxref("Element.undoScope")}} {{experimental_inline}}</dt>
 <dd>Is a {{jsxref("Boolean")}} indicating if the element is an undo scope host, or not.</dd>
</dl>

<div class="note">
<p><strong>Note:</strong> DOM Level 3 defined <code>namespaceURI</code>, <code>localName</code> and <code>prefix</code> on the {{domxref("Node")}} interface. In DOM4 they were moved to <code>Element</code>.</p>

<p>This change is implemented in Chrome since version 46.0 and Firefox since version 48.0.</p>
</div>

<h3 id="Handlers" name="Handlers">事件處理器</h3>

<dl>
 <dt>{{ domxref("Element.ongotpointercapture") }}</dt>
 <dd>Returns the event handler for the {{event("gotpointercapture")}} event type.</dd>
 <dt>{{ domxref("Element.onlostpointercapture") }}</dt>
 <dd>Returns the event handler for the {{event("lostpointercapture")}} event type.</dd>
 <dt>{{ domxref("Element.onwheel") }} {{ non-standard_inline() }}</dt>
 <dd>Returns the event handling code for the <code>wheel</code> event.</dd>
</dl>

<h2 id="Methods" name="Methods">方法</h2>

<p><em>Inherits methods from its parents {{domxref("Node")}}, and its own parent, {{domxref("EventTarget")}}<em>, and implements those of {{domxref("ParentNode")}}, {{domxref("ChildNode")}}<em>, {{domxref("NonDocumentTypeChildNode")}}, </em></em>and {{domxref("Animatable")}}.</em></p>

<dl>
 <dt>{{ domxref("EventTarget.addEventListener()") }}</dt>
 <dd>Registers an event handler to a specific event type on the element.</dd>
 <dt>{{domxref("Element.attachShadow()")}} {{experimental_inline}}</dt>
 <dd>Attatches a shadow DOM tree to the specified element and returns a reference to its {{domxref("ShadowRoot")}}.</dd>
 <dt>{{domxref("Element.animate()")}} {{experimental_inline}}</dt>
 <dd>A shortcut method to create and run an animation on an element. Returns the created Animation object instance.</dd>
 <dt>{{ domxref("Element.closest()")}} {{experimental_inline}}</dt>
 <dd>Returns the {{domxref("Element")}}, descendant of this element (or this element itself), that is the closest ancestor of the elements selected by the selectors given in parameter.</dd>
 <dt>{{ domxref("Element.createShadowRoot()")}} {{experimental_inline}} {{deprecated_inline()}}</dt>
 <dd>Creates a <a href="/en-US/docs/Web/Web_Components/Shadow_DOM">shadow DOM</a> on on the element, turning it into a shadow host. Returns a {{domxref("ShadowRoot")}}.</dd>
 <dt>{{ domxref("EventTarget.dispatchEvent()") }}</dt>
 <dd>Dispatches an event to this node in the DOM and returns a {{jsxref("Boolean")}} that indicates that at least one handler has not canceled it.</dd>
 <dt>{{domxref("Element.find()")}}{{experimental_inline}}</dt>
 <dd>...</dd>
 <dt>{{domxref("Element.findAll()")}}{{experimental_inline}}</dt>
 <dd>...</dd>
 <dt>{{domxref("Element.getAnimations()")}} {{experimental_inline}}</dt>
 <dd>Returns an array of Animation objects currently active on the element.</dd>
 <dt>{{ domxref("Element.getAttribute()") }}</dt>
 <dd>Retrieves the value of the named attribute from the current node and returns it as an {{jsxref("Object")}}.</dd>
 <dt>{{ domxref("Element.getAttributeNames()") }}</dt>
 <dd> </dd>
 <dt>{{ domxref("Element.getAttributeNS()") }}</dt>
 <dd>Retrieves the value of the attribute with the specified name and namespace, from the current node and returns it as an {{jsxref("Object")}}.</dd>
 <dt>{{ domxref("Element.getAttributeNode()") }} {{obsolete_inline}}</dt>
 <dd>Retrieves the node representation of the named attribute from the current node and returns it as an {{ domxref("Attr") }}.</dd>
 <dt>{{ domxref("Element.getAttributeNodeNS()") }} {{obsolete_inline}}</dt>
 <dd>Retrieves the node representation of the attribute with the specified name and namespace, from the current node and returns it as an {{ domxref("Attr") }}.</dd>
 <dt>{{ domxref("Element.getBoundingClientRect()") }}</dt>
 <dd>...</dd>
 <dt>{{ domxref("Element.getClientRects()") }}</dt>
 <dd>Returns a collection of rectangles that indicate the bounding rectangles for each line of text in a client.</dd>
 <dt>{{domxref("Element.getDestinationInsertionPoints()")}} {{experimental_inline}}</dt>
 <dd>…</dd>
 <dt>{{ domxref("Element.getElementsByClassName()") }}</dt>
 <dd>Returns a live {{ domxref("HTMLCollection") }} that contains all descendants of the current element that possess the list of classes given in the parameter.</dd>
 <dt>{{ domxref("Element.getElementsByTagName()") }}</dt>
 <dd>Returns a live {{ domxref("HTMLCollection") }} containing all descendant elements, of a particular tag name, from the current element.</dd>
 <dt>{{ domxref("Element.getElementsByTagNameNS()") }}</dt>
 <dd>Returns a live {{ domxref("HTMLCollection") }} containing all descendant elements, of a particular tag name and namespace, from the current element.</dd>
 <dt>{{ domxref("Element.hasAttribute()") }}</dt>
 <dd>Returns a {{jsxref("Boolean")}} indicating if the element has the specified attribute or not.</dd>
 <dt>{{ domxref("Element.hasAttributeNS()") }}</dt>
 <dd>Returns a {{jsxref("Boolean")}} indicating if the element has the specified attribute, in the specified namespace, or not.</dd>
 <dt>{{ domxref("Element.hasAttributes()") }}</dt>
 <dd>Returns a {{jsxref("Boolean")}} indicating if the element has one or more HTML attributes present.</dd>
 <dt>{{ domxref("Element.insertAdjacentElement") }} {{experimental_inline}}</dt>
 <dd>Inserts a given element node at a given position relative to the element it is invoked upon.</dd>
 <dt>{{ domxref("Element.insertAdjacentHTML") }} {{experimental_inline}}</dt>
 <dd>Parses the text as HTML or XML and inserts the resulting nodes into the tree in the position given.</dd>
 <dt>{{ domxref("Element.insertAdjacentText") }} {{experimental_inline}}</dt>
 <dd>Inserts a given text node at a given position relative to the element it is invoked upon.</dd>
 <dt>{{ domxref("Element.matches()") }}<code> </code>{{experimental_inline}}</dt>
 <dd>Returns a {{jsxref("Boolean")}} indicating whether or not the element would be selected by the specified selector string.</dd>
 <dt>{{ domxref("Element.querySelector()") }}</dt>
 <dd>Returns the first {{ domxref("Node") }} which matches the specified selector string relative to the element.</dd>
 <dt>{{ domxref("Element.querySelectorAll") }}</dt>
 <dd>Returns a {{ domxref("NodeList") }} of nodes which match the specified selector string relative to the element.</dd>
 <dt>{{ domxref("Element.releasePointerCapture")}}</dt>
 <dd>Releases (stops) pointer capture that was previously set for a specific {{domxref("PointerEvent","pointer event")}}.</dd>
 <dt>{{domxref("ChildNode.remove()")}} {{experimental_inline}}</dt>
 <dd>Removes the element from the children list of its parent.</dd>
 <dt>{{ domxref("Element.removeAttribute()") }}</dt>
 <dd>Removes the named attribute from the current node.</dd>
 <dt>{{ domxref("Element.removeAttributeNS()") }}</dt>
 <dd>Removes the attribute with the specified name and namespace, from the current node.</dd>
 <dt>{{ domxref("Element.removeAttributeNode()") }} {{obsolete_inline}}</dt>
 <dd>Removes the node representation of the named attribute from the current node.</dd>
 <dt>{{ domxref("EventTarget.removeEventListener()") }}</dt>
 <dd>Removes an event listener from the element.</dd>
 <dt>{{ domxref("Element.requestFullscreen()") }} {{experimental_inline}}</dt>
 <dd>Asynchronously asks the browser to make the element full-screen.</dd>
 <dt>{{ domxref("Element.requestPointerLock()")}} {{experimental_inline}}</dt>
 <dd>Allows to asynchronously ask for the pointer to be locked on the given element.</dd>
</dl>

<dl>
 <dt>{{ domxref("Element.scrollIntoView()") }} {{experimental_inline}}</dt>
 <dd>Scrolls the page until the element gets into the view.</dd>
 <dt>{{ domxref("Element.setAttribute()") }}</dt>
 <dd>Sets the value of a named attribute of the current node.</dd>
 <dt>{{ domxref("Element.setAttributeNS()") }}</dt>
 <dd>Sets the value of the attribute with the specified name and namespace, from the current node.</dd>
 <dt>{{ domxref("Element.setAttributeNode()") }} {{obsolete_inline}}</dt>
 <dd>Sets the node representation of the named attribute from the current node.</dd>
 <dt>{{ domxref("Element.setAttributeNodeNS()") }} {{obsolete_inline}}</dt>
 <dd>Setw the node representation of the attribute with the specified name and namespace, from the current node.</dd>
 <dt>{{ domxref("Element.setCapture()") }} {{non-standard_inline}}</dt>
 <dd>Sets up mouse event capture, redirecting all mouse events to this element.</dd>
 <dt>{{domxref("Element.setPointerCapture()")}}</dt>
 <dd>Designates a specific element as the capture target of future {{domxref("PointerEvent","pointer events")}}.</dd>
</dl>

<h2 id="規範">規範</h2>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td>{{SpecName('Shadow DOM')}}</td>
   <td>{{Spec2('Shadow DOM')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName("Web Animations", '', '')}}</td>
   <td>{{Spec2("Web Animations")}}</td>
   <td>Added the <code>getAnimations()</code> method.</td>
  </tr>
  <tr>
   <td>{{SpecName('Undo Manager', '', 'Element')}}</td>
   <td>{{Spec2('Undo Manager')}}</td>
   <td>Added the <code>undoScope</code> and <code>undoManager</code> properties.</td>
  </tr>
  <tr>
   <td>{{SpecName('Pointer Events 2', '#extensions-to-the-element-interface', 'Element')}}</td>
   <td>{{Spec2('Pointer Events 2')}}</td>
   <td>Added the following event handlers: <code>ongotpointercapture</code> and <code>onlostpointercapture</code>.<br>
    Added the following methods: <code>setPointerCapture()</code> and <code>releasePointerCapture()</code>.</td>
  </tr>
  <tr>
   <td>{{SpecName('Pointer Events', '#extensions-to-the-element-interface', 'Element')}}</td>
   <td>{{Spec2('Pointer Events')}}</td>
   <td>Added the following event handlers: <code>ongotpointercapture</code> and <code>onlostpointercapture</code>.<br>
    Added the following methods: <code>setPointerCapture()</code> and <code>releasePointerCapture()</code>.</td>
  </tr>
  <tr>
   <td>{{SpecName('Selectors API Level 2', '#interface-definitions', 'Element')}}</td>
   <td>{{Spec2('Selectors API Level 2')}}</td>
   <td>Added the following methods:<code> matches()</code> (implemented as <code>mozMatchesSelector()</code>), <code>find()</code>, <code>findAll()</code>.</td>
  </tr>
  <tr>
   <td>{{SpecName('Selectors API Level 1', '#interface-definitions', 'Element')}}</td>
   <td>{{Spec2('Selectors API Level 1')}}</td>
   <td>Added the following methods: <code>querySelector()</code> and <code>querySelectorAll()</code>.</td>
  </tr>
  <tr>
   <td>{{SpecName('Pointer Lock', 'index.html#element-interface', 'Element')}}</td>
   <td>{{Spec2('Pointer Lock')}}</td>
   <td>Added the <code>requestPointerLock()</code> method.</td>
  </tr>
  <tr>
   <td>{{SpecName('Fullscreen', '#api', 'Element')}}</td>
   <td>{{Spec2('Fullscreen')}}</td>
   <td>Added the <code>requestFullscreen()</code> method.</td>
  </tr>
  <tr>
   <td>{{SpecName('DOM Parsing', '#extensions-to-the-element-interface', 'Element')}}</td>
   <td>{{Spec2('DOM Parsing')}}</td>
   <td>Added the following properties: <code>innerHTML</code>, and <code>outerHTML</code>.<br>
    Added the following method: <code>insertAdjacentHTML()</code>.</td>
  </tr>
  <tr>
   <td>{{SpecName('CSSOM View', '#extensions-to-the-element-interface', 'Element')}}</td>
   <td>{{Spec2('CSSOM View')}}</td>
   <td>Added the following properties: <code>scrollTop</code>, <code>scrollLeft</code>, <code>scrollWidth</code>, <code>scrollHeight</code>, <code>clientTop</code>, <code>clientLeft</code>, <code>clientWidth</code>, and <code>clientHeight</code>.<br>
    Added the following methods: <code>getClientRects()</code>, <code>getBoundingClientRect()</code>, and <code>scrollIntoView()</code>.</td>
  </tr>
  <tr>
   <td>{{SpecName('Element Traversal', '#ecmascript-bindings', 'Element')}}</td>
   <td>{{Spec2('Element Traversal')}}</td>
   <td>Added inheritance of the {{domxref("ElementTraversal")}} interface.</td>
  </tr>
  <tr>
   <td>{{SpecName('DOM WHATWG', '#interface-element', 'Element')}}</td>
   <td>{{Spec2('DOM WHATWG')}}</td>
   <td>Removed the following methods: <code>closest()</code>, <code>setIdAttribute()</code>, <code>setIdAttributeNS()</code>, and <code>setIdAttributeNode()</code>.<br>
    Removed the <code>schemaTypeInfo</code> property.<br>
    Modified the return value of <code>getElementsByTag()</code> and <code>getElementsByTagNS()</code>.<br>
    Moved <code>hasAttributes()</code> from the <code>Node</code> interface to this one.<br>
    Inserted <code>insertAdjacentElement()</code> and <code>insertAdjacentText()</code>.</td>
  </tr>
  <tr>
   <td>{{SpecName('DOM3 Core', 'core.html#ID-745549614', 'Element')}}</td>
   <td>{{Spec2('DOM3 Core')}}</td>
   <td>Added the following methods: <code>setIdAttribute()</code>, <code>setIdAttributeNS()</code>, and <code>setIdAttributeNode()</code>. These methods were never implemented and have been removed in later specifications.<br>
    Added the <code>schemaTypeInfo</code> property. This property was never implemented and has been removed in later specifications.</td>
  </tr>
  <tr>
   <td>{{SpecName('DOM2 Core', 'core.html#ID-745549614', 'Element')}}</td>
   <td>{{Spec2('DOM2 Core')}}</td>
   <td>The <code>normalize()</code> method has been moved to {{domxref("Node")}}.</td>
  </tr>
  <tr>
   <td>{{SpecName('DOM1', 'level-one-core.html#ID-745549614', 'Element')}}</td>
   <td>{{Spec2('DOM1')}}</td>
   <td>Initial definition.</td>
  </tr>
 </tbody>
</table>

<h2 id="瀏覽器相容性">瀏覽器相容性</h2>

{{Compat("api.Element")}}