Answers for "js get all element of class"

javascript get all elements with class

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

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

javascript get all classes

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

javascript get all elements by class starting with

document.querySelectorAll("[class^=page]")