HTML tutorial
CSS3 tutorial
Bootstrap tutorial
JavaScript tutorial
JQuery tutorial
AngularJS tutorial
React tutorial
NodeJS tutorial
PHP tutorial
Python tutorial
Python3 tutorial
Django tutorial
Linux tutorial
Docker tutorial
Ruby tutorial
Java tutorial
C tutorial
C ++ tutorial
Perl tutorial
JSP tutorial
Lua tutorial
Scala tutorial
Go tutorial
ASP.NET tutorial
C # tutorial
An HTMLCollection is an array-like collection (list) of HTML elements
An HTMLCollection is an array-like collection (list) of HTML elements.
The elements in a collection can be accessed by index (starts at 0).
An HTMLCollection is almost the same as a NodeList.
See the description below.
The getElementsByTagName() Method
The following properties and methods can be used on an HTMLCollection:
| Name | Description |
|---|---|
| length | Returns the number of elements in an HTMLCollection |
| item() | Returns the element at a specified index |
| namedItem() | Returns the element with a specified id |
Get all parapgraphs:
const elements = document.getElementsByTagName("p");
The number of <p> elements in the document are:
const elements = document.getElementsByTagName("p");
let numb = elements.length;
Loop over the elements in an HTMLCollection:
const elements = document.getElementsByTagName("*");
for (let i = 0; i < elements.length; i++) {
.. some code ..
}
An HTMLCollection is not an Array!
An HTMLCollection may look like an array, but it is not.
You can loop through an HTMLCollection and refer to its elements with an index.
But you cannot use Array methods like push(), pop(), or join() on an HTMLCollection.
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.
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.
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.