JavaScript HTML DOM Collections
The HTMLCollection Object
The getElementsByTagName() method returns an HTMLCollection object, which is an array-like list (collection) of HTML elements.
Example: Selecting All <p> Elements
const myCollection = document.getElementsByTagName("p");
The elements in the collection can be accessed using an index number. To access the second <p> element, you can write:
myCollection[1];
Note: The index starts at 0.
HTMLCollection Length
The length property defines the number of elements in an HTMLCollection:
Example:
myCollection.length;
The length property is useful when you want to loop through the elements in a collection:
Example: Changing the Text Color of All <p> Elements
const myCollection = document.getElementsByTagName("p");
for (let i = 0; i < myCollection.length; i++)
{ myCollection[i].style.color = "red";}An HTMLCollection is NOT an Array!
An HTMLCollection may look like an array, but it is not. You can loop through the list and refer to the elements with a number, just like an array. However, you cannot use array methods like valueOf(), pop(), push(), or join() on an HTMLCollection.
