this.js

const a = {
  a: 'a'
};

const obj = {
  getThis: () => this,
  getThis2 () {
    return this;
  }
};

obj.getThis3 = obj.getThis.bind(obj);
obj.getThis4 = obj.getThis2.bind(obj);
const answers = [
  obj.getThis(),
  obj.getThis.call(a),
  obj.getThis2(),
  obj.getThis2.call(a),
  obj.getThis3(),
  obj.getThis3.call(a),
  obj.getThis4(),
  obj.getThis4.call(a)
];

console.log(answers)