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

function Dog(name) {
  Animal.call(this, name);
}
Dog.prototype = Object.create(Animal.prototype);
Dog.prototype.constructor = Dog;
Dog.prototype.speak = function () {
  return `${Animal.prototype.speak.call(this)} (bark)`;
};

const d = new Dog('Rex');
console.log(
  d.speak(),
  d instanceof Animal,
  d.constructor === Dog,
  Object.getPrototypeOf(d) === Dog.prototype
);

export {};