Web/API/HTMLCollection

The HTMLCollection interface represents a generic collection (array-like object similar to arguments) of elements (in document order) and offers methods and properties for selecting from the list.

Note: This interface is called HTMLCollection for historical reasons (before the modern DOM, collections implementing this interface could only have HTML elements as their items).

An HTMLCollection in the HTML DOM is live; it is automatically updated when the underlying document is changed.

Properties

HTMLCollection.length Read only: Returns the number of items in the collection.

Methods

HTMLCollection.item(): Returns the specific node at the given zero-based index into the list. Returns null if the index is out of range.; An alternative to accessing collection[i] (which instead returns undefined when i is out-of-bounds). This is mostly useful for non-JavaScript DOM implementations.
HTMLCollection.namedItem(): Returns the specific node whose ID or, as a fallback, name matches the string specified by name. Matching by name is only done as a last resort, only in HTML, and only if the referenced element supports the name attribute. Returns null if no node exists by the given name.; An alternative to accessing collection[name] (which instead returns undefined when name does not exist). This is mostly useful for non-JavaScript DOM implementations.

Usage in JavaScript

HTMLCollection also exposes its members directly as properties by both name and index. HTML IDs may contain : and . as valid characters, which would necessitate using bracket notation for property access. Currently HTMLCollections does not recognize purely numeric IDs, which would cause conflict with the array-style access, though HTML5 does permit these.

For example, assuming there is one <form> element in the document and its id is myForm:

var elem1, elem2;

// document.forms is an HTMLCollection

elem1 = document.forms[0];
elem2 = document.forms.item(0);

alert(elem1 === elem2); // shows: "true"

elem1 = document.forms.myForm;
elem2 = document.forms.namedItem("myForm");

alert(elem1 === elem2); // shows: "true"

elem1 = document.forms["named.item.with.periods"];

Specifications

Specification	Status	Comment
DOMThe definition of 'HTMLCollection' in that specification.	Living Standard

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`HTMLCollection`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 8	Opera Full support 8	Safari Full support 4	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 3.2	Samsung Internet Android Full support 1.0
`item`	Chrome Full support Yes	Edge Full support 12	Firefox Full support Yes	IE ?	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support Yes	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes
`length`	Chrome Full support Yes	Edge Full support 12	Firefox Full support Yes	IE ?	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support Yes	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes
`namedItem`	Chrome Full support Yes	Edge Full support 12	Firefox Full support Yes	IE Full support Yes	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support Yes	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes

Legend

Full support: Full support
Compatibility unknown: Compatibility unknown