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DocumentFragment.querySelector

The DocumentFragment.querySelector() method returns the first element, or null if no matches are found, within the DocumentFragment (using depth-first pre-order traversal of the document's nodes) that matches the specified group of selectors.

If the selector matches an ID and this ID is erroneously used several times in the document, it returns the first matching element.

If the selectors specified in parameter are invalid a DOMException with a SYNTAX_ERR value is raised.

Syntax

element = documentfragment.querySelector(selectors);

Parameters

selectors
Is a DOMString containing one or more CSS selectors separated by commas.

Examples

Basic example

In this basic example, the first element in the DocumentFragment with the class "myclass" is returned:

var el = documentfragment.querySelector(".myclass");

CSS syntax and the method's argument

The string argument pass to querySelector must follow the CSS syntax. To match ID or selectors that do not follow the CSS syntax (by using semicolon or space inappropriately for example), it's mandatory to escape the wrong character with a double back slash:

<div id="foo\bar"></div>
<div id="foo:bar"></div>

<script>
document.querySelector('#foo\bar')    // Does not match anything
document.querySelector('#foo\\\\bar') // Match the first div
document.querySelector('#foo:bar')     // Does not match anything
document.querySelector('#foo\\:bar')   // Match the second div
</script>

Specifications

Specification Status Comment
Selectors API Level 2
The definition of 'DocumentFragment.querySelector' in that specification.
Working Draft No change from Selectors API Level 1
Selectors API Level 1
The definition of 'DocumentFragment.querySelector' in that specification.
Recommendation Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 1 3.5 (1.9.1) 8.0 10.0 3.2 (525.3)
Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support 2.1 1.0 (1.9.1) 9.0 10.0 3.2

See also

© 2005–2017 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/DocumentFragment/querySelector