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Prototypal Inheritance

Object Literal Based​

// Define a prototype object
const animal = {
  eats: true,
  walk() {
    console.log("Animal walks");
  }
};

// Create a new object that inherits from 'animal'
const dog = Object.create(animal);
dog.bark = function() {
  console.log("Dog barks");
};

dog.walk(); // Inherited from 'animal': "Animal walks"
dog.bark(); // Specific to 'dog': "Dog barks"

console.log(dog.eats); // Inherited property: true

Constructor Functions and Prototypal Inheritance​

function Person(name) {
  this.name = name;
}

Person.prototype.greet = function() {
  console.log("Hello, my name is " + this.name);
};

const john = new Person("John");
john.greet(); // "Hello, my name is John"

ES6 Classes and Prototypes​

class Animal {
  constructor(name) {
    this.name = name;
  }
  
  speak() {
    console.log(`${this.name} makes a noise`);
  }
}

class Dog extends Animal {
  speak() {
    console.log(`${this.name} barks`);
  }
}

const myDog = new Dog("Rex");
myDog.speak(); // Rex barks