Mastering Polymorphism and Inheritance in JavaScript

A Practical Guide to Supercharging Your Code

Photo by Gabriel Ramos on Unsplash

Polymorphism and inheritance are two fundamental concepts in object-oriented programming (OOP) that can significantly enhance your JavaScript skills. While they may sound intimidating at first, these concepts are actually quite straightforward and can supercharge your code’s flexibility and reusability.

Understanding Polymorphism

Polymorphism is a Greek term that literally means “many shapes.” In the context of programming, it refers to the ability of objects to take on multiple forms. In other words, objects of different classes can respond to the same method call in different ways.

Here’s a simple example:

class Animal {
  makeSound() {
    console.log("The animal makes a sound.");
  }
}

class Dog extends Animal {
  makeSound() {
    console.log("The dog barks.");
  }
}

class Cat extends Animal {
  makeSound() {
    console.log("The cat meows.");
  }
}

let pet1 = new Dog();
let pet2 = new Cat();

pet1.makeSound(); // Output: The dog barks.
pet2.makeSound(); // Output: The cat meows.

In this example, both Dog and Cat classes override the makeSound method inherited from the Animal class. When we call makeSound on instances of Dog and…