functional-prototypal-inheritance-of-cats.js

// https://nationalkitty.com/cat-ancestry-where-do-cats-come-from/
const pantherinae = {
  roar: function () {
    console.log(`${this.name} is roaring!`);
  },
  domesticated: false,
  size: "large",
  sound: "roar",
};

const acinonychinae = Object.create(pantherinae, {
  roar: { value: undefined },
  size: { value: "medium" },
  sound: { value: undefined },
});

const felisSilvestrisCatus = Object.create(acinonychinae, {
  purr: {
    value: function () {
      return `${this.name} is purring!`;
    },
  },
  sound: { value: "purr" },
});

const em = Object.create(felisSilvestrisCatus, {
  domesticated: { value: true },
  name: { value: "Em" },
  size: { value: "small" },
});

const cheetah = Object.create(acinonychinae);

const lion = Object.create(pantherinae, {
  name: { value: "Alex" },
});

console.log(
  `${em.name} is ${em.size} and can ${
    em.sound
  }(${em.purr()}), but cannot roar(${em.roar}).`
);
console.log(`Is a cat domesticated? ${em.domesticated}`);

lion.roar();

console.log(`Is a lion domesticated? ${lion.domesticated}`);
console.log(`Is a cheetah domesticated? ${cheetah.domesticated}`);
console.log(`What sound does a cheetah make? ${cheetah.sound}`);