how to get all elements of a class javascript code example

Example 1: javascript get all elements with class

const allElementContainGrepperClassName = document.querySelectorAll('.grepper');
// => return array of all elements 

const firstElementContainGrepperClassName = document.querySelector('.grepper');

Example 2: how to get element by class name javascript

document.getElementsByClassName("legend").style.display="none";

Example 3: javascript get all classes

var allHiddenElements = document.getElementsByClassName("hidden");