ParentNode.querySelectorAll() - Web APIs 编辑

The ParentNode mixin defines the querySelectorAll() method as returning a NodeList representing a list of elements matching the specified group of selectors which are descendants of the object on which the method was called.

If you need only a single result, consider the querySelector() method instead.

Note: This method is implemented as Element.querySelectorAll(), Document.querySelectorAll(), and DocumentFragment.querySelectorAll()

Syntax

elementList = parentNode.querySelectorAll(selectors);

Parameters

selectors

A DOMString containing one or more selectors to match against. This string must be a valid CSS selector string; if it's not, a SyntaxError exception is thrown. See Locating DOM elements using selectors for more information about using selectors to identify elements. Multiple selectors may be specified by separating them using commas.

Note: Characters which are not part of standard CSS syntax must be escaped using a backslash character. Since JavaScript also uses backslash escaping, special care must be taken when writing string literals using these characters. See Escaping special characters for more information.

Return value

A non-live NodeList containing one Element object for each descendant node that matches at least one of the specified selectors.

Note: If the specified selectors include a CSS pseudo-element, the returned list is always empty.

Exceptions

SyntaxError

The syntax of the specified selectors string is not valid.

Examples

To obtain a NodeList of all of the <p> elements in the document:

var matches = document.querySelectorAll("p");

This example returns a list of all <div> elements within the document with a class of either note or alert:

var matches = document.querySelectorAll("div.note, div.alert");

Here, we get a list of <p> elements whose immediate parent element is a <div> with the class highlighted and which are located inside a container whose ID is test.

var container = document.querySelector("#test");
var matches = container.querySelectorAll("div.highlighted > p");

This example uses an attribute selector to return a list of the <iframe> elements in the document that contain an attribute named data-src:

var matches = document.querySelectorAll("iframe[data-src]");

Here, an attribute selector is used to return a list of the list items contained within a list whose ID is userlist which have a data-active attribute whose value is 1:

var container = document.querySelector("#userlist");
var matches = container.querySelectorAll("li[data-active=1]");

User notes

querySelectorAll() behaves differently than most common JavaScript DOM libraries, which might lead to unexpected results.

HTML

Consider this HTML, with its three nested <div> blocks.

<div class="outer">
  <div class="select">
    <div class="inner">
    </div>
  </div>
</div>

JavaScript

var select = document.querySelector('.select');
var inner = select.querySelectorAll('.outer .inner');
inner.length; // 1, not 0!

In this example, when selecting .outer .inner in the context the <div> with the class select, the element with the class .inner is still found, even though .outer is not a descendant of the base element on which the search is performed (.select). By default, querySelectorAll() only verifies that the last element in the selector is within the search scope.

The :scope pseudo-class restores the expected behavior, only matching selectors on descendants of the base element:

var select = document.querySelector('.select');
var inner = select.querySelectorAll(':scope .outer .inner');
inner.length; // 0

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• Locating DOM elements using selectors
• Code snippets for querySelector()
• Attribute selectors in the CSS Guide
• Attribute selectors in the MDN Learning Area
• This method is available as Element.querySelectorAll(), Document.querySelectorAll(), and DocumentFragment.querySelectorAll()