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Document.createElement() - Web APIs 编辑

In an HTML document, the document.createElement() method creates the HTML element specified by tagName, or an HTMLUnknownElement if tagName isn't recognized.

Syntax

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

Parameters

tagName: 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").
options Optional: An optional ElementCreationOptions object, containing a single property named is, whose value is the tag name of a custom element previously defined via customElements.define(). See Web component example for more details.

Examples

Basic example

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

HTML

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

JavaScript

document.body.onload = addElement;

function addElement () {
  // create a new div element
  const newDiv = document.createElement("div");

  // and give it some content
  const newContent = document.createTextNode("Hi there and greetings!");

  // add the text node to the newly created div
  newDiv.appendChild(newContent);

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

The following example snippet is taken from our expanding-list-web-component example (see it live also). In this case, our custom element extends the HTMLUListElement, which represents the <ul> element.

// Create a class for the element
class ExpandingList extends HTMLUListElement {
  constructor() {
    // Always call super first in constructor
    super();

    // constructor definition left out for brevity
    ...
  }
}

// Define the new element
customElements.define('expanding-list', ExpandingList, { extends: "ul" });

If we wanted to create an instance of this element programmatically, we'd use a call along the following lines:

let expandingList = document.createElement('ul', { is : 'expanding-list' })

The new element will be given an is attribute whose value is the custom element's tag name.

Note: 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.

Specifications

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

Browser compatibility

BCD tables only load in the browser

Document.createElement() - Web APIs 编辑

Syntax

Parameters

Return value

Examples

Basic example

HTML

JavaScript

Web component example

Specifications

Browser compatibility

See also

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友情链接

Document.createElement() - Web APIs 编辑

HTML

JavaScript

如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

词条统计

友情链接

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。