Locating DOM elements using selectors
The Selectors API provides methods that make it quick and easy to retrieve Element
nodes from the DOM by matching against a set of selectors. This is much faster than past techniques, wherein it was necessary to, for example, use a loop in JavaScript code to locate the specific items you needed to find.
The NodeSelector interface
This specification adds two new methods to any objects implementing the Document
, DocumentFragment
, or Element
interfaces:
-
querySelector
-
Returns the first matching
Element
node within the node's subtree. If no matching node is found,null
is returned. -
querySelectorAll
-
Returns a
NodeList
containing all matchingElement
nodes within the node's subtree, or an emptyNodeList
if no matches are found.
NodeList
returned by querySelectorAll()
is not live. This is different from other DOM querying methods that return live node lists.You may find examples and details by reading the documentation for the querySelector()
and querySelectorAll()
methods, as well as in the article Code snippets for querySelector.
Selectors
The selector methods accept one or more comma-separated selectors to determine what element or elements should be returned. For example, to select all paragraph (p
) elements in a document whose CSS class is either warning
or note
, you can do the following:
var special = document.querySelectorAll( "p.warning, p.note" );
You can also query by ID. For example:
var el = document.querySelector( "#main, #basic, #exclamation" );
After executing the above code, el
contains the first element in the document whose ID is one of main
, basic
, or exclamation
.
You may use any CSS selectors with the querySelector()
and querySelectorAll()
methods.
See also
- Selectors API
element.querySelector
element.querySelectorAll
document.querySelector
document.querySelectorAll
- Code snippets for querySelector
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/document_object_model/locating_dom_elements_using_selectors