kitty.js

let log = console.log;

let myObj = {}; // new Object()
// log(myObj.constructor); // function Object(){}
// log(myObj.__proto__ === myObj.constructor.prototype);

function Cat() {
  //constructor for kitty
}
let kitty = new Cat();
// log(kitty.__proto__ === Cat.prototype);
// log(kitty.__proto__.__proto__ === Object.prototype);
// log(Object.prototype.__proto__);

function Animal() {}

Object.setPrototypeOf(Cat.prototype, Animal.prototype);
log(kitty.__proto__); // Cat{}
log(kitty.__proto__.__proto__); // Animal {}
log(kitty.__proto__.__proto__.__proto__); // {}
log(kitty.__proto__.__proto__.__proto__.__proto__); // null