Can you give me some examples with getElementsByClassName ?

Question

I do not understand how to use

Answer 1

unlike getElementById, getElementsByClassName returns a collection (basically an array) of the elements that were found in the DOM.

so accessing an element would be done by square brackets [ ] and an index

example:
given this html

<div class="numbers">1</div>
<div class="numbers">2</div>
<div class="numbers">3</div>

if you want to change the color of the number 2 to green, you can do something like this in JS

var number_2 = document.getElementsByClassName("numbers")[1];
number_2.style.color = "green";

Answer 2

"The getElementsByClassName() method returns a collection of all elements in the document with the specified class name, as a NodeList object.

The NodeList object represents a collection of nodes. The nodes can be accessed by index numbers. The index starts at 0.

Example

Get all elements with the specified class name:

var x =document.getElementsByClassName("example");"

Source: https://www.w3schools.com/jsref/met_document_getelementsbyclassname.asp

Answer 3

Thanks a lot