HTML 文件中,Document.createElement() 方法可以依指定的標籤名稱(tagName)建立 HTML 元素,或是在未定義標籤名稱下建立一個 HTMLUnknownElement。在 XUL 文件中,Document.createElement() 將會建立指定的 XUL 元素。而在其它文件,則會建立一個 namespace URI 為 null 的元素。

若要明確指定元素的 namespace URI,請使用 document.createElementNS()


var element = document.createElement(tagName[, options]);


A string that specifies the type of element to be created. The nodeName of the created element is initialized with the value of tagName. Don't use qualified names (like "html:a") with this method. When called on an HTML document, createElement() converts tagName to lower case before creating the element. In Firefox, Opera, and Chrome, createElement(null) works like createElement("null").
An optional ElementCreationOptions object containing a single property named is, whose value is the tag name for a custom element previously defined using customElements.define(). For backwards compatibility with previous versions of the Custom Elements specification, some browsers will allow you to pass a string here instead of an object, where the string's value is the custom element's tag name. See Extending native HTML elements for more information on how to use this parameter.
The new element will be given an is attribute whose value is the custom element's tag name. Custom elements are an experimental feature only available in some browsers.


The new Element.


This creates a new <div> and inserts it before the element with the ID "div1".


<!DOCTYPE html>
  <title>||Working with elements||</title>
  <div id="div1">The text above has been created dynamically.</div>


document.body.onload = addElement;

function addElement () { 
  // create a new div element 
  // and give it some content 
  var newDiv = document.createElement("div"); 
  var newContent = document.createTextNode("Hi there and greetings!"); 
  newDiv.appendChild(newContent); //add the text node to the newly created div. 

  // add the newly created element and its content into the DOM 
  var currentDiv = document.getElementById("div1"); 
  document.body.insertBefore(newDiv, currentDiv); 


Specification Status Comment
The definition of 'Document.createElement' in that specification.
Living Standard  


We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Yes) (Yes) (Yes)[1][2] (Yes) (Yes) (Yes)
options argument (Yes)[3] ? 50 (50)[4][5] ? ? ?
Feature Android Android Webview Edge Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile Chrome for Android
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)
options argument (Yes) (Yes)[3] ? ? ? ? ? (Yes)[3]

[1] Starting with Gecko 22.0 (Firefox 22.0 / Thunderbird 22.0 / SeaMonkey 2.19) createElement() no longer uses the HTMLSpanElement interface when the argument is "bgsounds", "multicol", or "image".  Instead, HTMLUnknownElement is used for "bgsound" and "multicol" and HTMLElement HTMLElement is used for "image".

[2] The Gecko implementation of createElement doesn't conform to the DOM spec for XUL and XHTML documents: localName and namespaceURI are not set to null on the created element. See bug 280692 for details.

[3] In previous versions of the specification, this argument was just a string whose value was the custom element's tag name. For example: document.createElement("button", "custom-button") rather than document.createElement("button", {id: "custom-button"}). For the sake of backwards compatibility, Chrome accepts both forms.

[4] See [3] above: like Chrome, Firefox accepts a string instead of an object here, but only from version 51 onwards. In version 50,  options must be an object.

[5] To experiment with custom elements in Firefox, you must set the dom.webcomponents.enabled and dom.webcomponents.customelements.enabled preferences to true.



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