Returns a static (not live) NodeList
of all elements descended from the element on which it is invoked that matches the specified group of CSS selectors. (The base element itself is not included, even if it matches.)
Note: The definition of this API was moved to the ParentNode
interface.
elementList = baseElement.querySelectorAll(selectors);
where:
elementList
NodeList[elements]
]
of element objects.baseElement
selectors
This example returns a list of all the p
elements in the HTML document body:
let matches = document.body.querySelectorAll('p');
This example returns a list of p
children elements under a container, whose parent is a div
that has the class 'highlighted':
let el = document.querySelector('#test'); //return an element with id='test' let matches = el.querySelectorAll('div.highlighted > p'); // return a NodeList of p wrapped in a div with attribute class "highlighted"
This example returns a list of iframe
elements that contain a attribute 'data-src':
let matches = el.querySelectorAll('iframe[data-src]');
If the specified "selectors" are not found inside the DOM of the page, the method queryselectorAll
returns an empty NodeList as specified below:
> let x = document.body.querySelectorAll('.highlighted'); //case: if the class highlighted doesn't exist in any attribute "class" of the DOM the result is > [] //empty NodeList
querySelectorAll()
was introduced in the WebApps API.
The string argument pass to querySelectorAll
must follow the CSS syntax. See document.querySelector
for a concrete example.
We could access a single item inside the NodeList in the following way:
let x = document.body.querySelectorAll('.highlighted'); x.length; //return the size of x x[i_item]; //where i_item has a value between 0 and x.length-1. The operator "[]" return as in an array the element at index "i_item"
We could iterate inside a NodeList with the construct for(....) {...}
as in the following code:
let x = document.body.querySelectorAll('.highlighted'); let index = 0; for( index=0; index < x.length; index++ ) { console.log(x[index]); }
So in the above way, it is possible to manage and modify the behaviour of the page.
querySelectorAll()
behaves differently than most common JavaScript DOM libraries, which might lead to unexpected results:
<div class="outer"> <div class="select"> <div class="inner"> </div> </div> </div>
let select = document.querySelector('.select'); let inner = select.querySelectorAll('.outer .inner'); inner.length; // 1, not 0!
In this example, when selecting .outer .inner
in the context of .select
, .inner
is still found, even though .outer
is not a descendant of the baseElement (.select
).
querySelectorAll()
only verifies that the last element in the selector is within the baseElement.
The :scope
pseudo-class restores the expected behavior, only matching selectors on descendants of the baseElement:
let select = document.querySelector('.select'); let inner = select.querySelectorAll(':scope .outer .inner'); inner.length; // 0
Specification | Status | Comment |
---|---|---|
Selectors API Level 1 The definition of 'querySelectorAll' in that specification. | Obsolete | Initial definition |
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 1 | 3.5 (1.9.1) | 8 | 10 | 3.2 (525.3) |
:scope pseudo-class | (Yes) | 32 | No support | 15[1] | 7.0 |
Feature | Android | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|
Basic support | (Yes) | 1.0 (1.9.1) | ? | ? | (Yes) |
:scope pseudo-class | ? | 32 | No support | No support | 7.0 |
[1] Supported in Opera 15+ by enabling the "Enable <style scoped>" or "Enable experimental Web Platform features" flag in chrome://flags
.
element.querySelector()
document.querySelectorAll()
document.querySelector()
querySelector
© 2005–2018 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/element/querySelectorAll