class Animal {
  constructor(name) {
    this.name = name;
  }
  speak() {
    return `${this.name} makes a sound`;
  }
}

class Dog extends Animal {
  speak() {
    return super.speak() + ' and barks';
  }
}

const pet = new Dog('Rex');
console.log(pet.speak());
console.log(pet instanceof Animal);
console.log(pet.constructor.name);

class DataProcessor {
  constructor(value) {
    this.value = value;
  }
  
  transform(fn) {
    return new DataProcessor(fn(this.value));
  }
  
  getValue() {
    return this.value;
  }
}

const multiply = x => x * 2;
const add = x => x + 10;
const square = x => x * x;

const result = new DataProcessor(5)
  .transform(multiply)
  .transform(add)
  .transform(square)
  .getValue();

console.log(result);