HTML DOM Document querySelectorAll()

Definition and Usage

The querySelectorAll() method returns all elements that matches a CSS selector(s).

The querySelectorAll() method returns a NodeList.

Chủ Đề Bài Viết: Queryselectorall

The querySelectorAll() method throws a SYNTAX_ERR exception if the selector(s) is invalid

The Difference Between an HTMLCollection and a NodeList

A NodeList and an HTMLcollection is very much the same thing.

Both are array-like collections (lists) of nodes (elements) extracted from a document. The nodes can be accessed by index numbers. The index starts at 0.

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Both have a length property that returns the number of elements in the list (collection).

An HTMLCollection is a collection of document elements.

A NodeList is a collection of document nodes (element nodes, attribute nodes, and text nodes).

HTMLCollection items can be accessed by their name, id, or index number.

NodeList items can only be accessed by their index number.

An HTMLCollection is always a live collection. Example: If you add a <li> element to a list in the DOM, the list in the HTMLCollection will also change.

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A NodeList is most often a static collection. Example: If you add a <li> element to a list in the DOM, the list in NodeList will not change.

The getElementsByClassName() and getElementsByTagName() methods return a live HTMLCollection.

The querySelectorAll() method returns a static NodeList.

The childNodes property returns a live NodeList.

Syntax

Parameters

Parameter Description CSS selectors Required.One or more CSS selectors.CSS selectors select HTML elements based on id, classes, types, attributes, values of attributes etc. For a full list, go to our CSS Selectors Reference. For multiple selectors, separate each selector with a comma (See “More Examples”).

Return Value

Type Description ObjectA NodeList object with the elements that matches the CSS selector(s). If no matches are found, an empty NodeList object is returned.

More Examples

Browser Support

document.querySelectorAll() is a DOM Level 3 (2004) feature.

It is fully supported in all browsers:

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Chrome IE Edge Firefox Safari Opera Yes 9-11 Yes Yes Yes Yes

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