Factory.js

// CLASSES

class Dog {
  constructor() {
    this.sound = 'woof';
  }
  talk() {
    console.log(this.sound);
  }
}

const sniffles = new Dog();
const fluffy = new Dog();

$(function() {
  // $('button.myButton').click(sniffles.talk); // => will not work
  // $('button.myButton').click(sniffles.talk.bind(sniffles)); // => will work
  // $('button.myButton').click(_ => sniffles.talk()); // => will work
});

// FACTORY FUNCTION

const dog = () => {
  const sound = 'woof';
  return {
    talk: () => console.log(sound),
  };
};
const sniffles = dog();

$(function() {
  $('button.myButton').click(sniffles.talk);
});