javascript get all elements with any class 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: javascript get all instances of a class

MyClass.allInstances = [];
MyClass.allInstances.push(this);
//However, you need some way to figure out when to remove instances from this array, or you'll leak memory.