If JavaScript objects were actors, polymorphism would be their superpower 🎭
It allows the same function name to behave differently depending on who’s calling it.

Think of saying “run”:

• A child runs playfully 👶
• A sprinter runs fast 🏃
• A computer program runs your code 🖥️

Same word. Different behavior.
That’s exactly what polymorphism means in JavaScript!

Let’s explore this in the most beginner-friendly way possible 👇

---

🌟 What Is Polymorphism?

Polymorphism = One interface, multiple forms

In simpler words:

🗣️ You call the same method, but each object executes it in its own way.

JavaScript uses polymorphism mainly through:

• Method overriding (most common)
• Method overloading (JS doesn’t have true overloading, but we mimic it)

---

🐾 Classic Example: Animals Making Sounds

class Animal {
  makeSound() {
    console.log("Some sound...");
  }
}

class Dog extends Animal {
  makeSound() {
    console.log("Woof!🐶");
  }
}

class Cat extends Animal {
  makeSound() {
    console.log("Meow!🐱");
  }
}

const animals = [new Animal(), new Dog(), new Cat()];

animals.forEach(a => a.makeSound());

Output:

Some sound...
Woof!🐶
Meow!🐱

Same method → makeSound()
Different behavior → based on class ✔

---

🎮 Real-Life Example: Payment System

class Payment {
  pay() {
    console.log("Processing payment...");
  }
}

class CreditCard extends Payment {
  pay() {
    console.log("Paid using Credit Card 💳");
  }
}

class UPI extends Payment {
  pay() {
    console.log("Paid using UPI 📱");
  }
}

function checkout(paymentMethod) {
  paymentMethod.pay();
}

checkout(new UPI());
checkout(new CreditCard());

You can plug in any payment method
and pay() will run the correct implementation.

That’s polymorphism in action — flexible, clean, future-friendly.

---

🚗 Another Example: Vehicles Move Differently

class Vehicle {
  move() {
    console.log("The vehicle is moving...");
  }
}

class Car extends Vehicle {
  move() {
    console.log("Car is driving on the road 🚗");
  }
}

class Plane extends Vehicle {
  move() {
    console.log("Plane is flying in the sky ✈️");
  }
}

const v = [new Car(), new Plane()];
v.forEach(item => item.move());

When you call move(), each vehicle responds in its unique way.

---

📌 Why Use Polymorphism?

✔ Cleaner code
✔ Easier to extend
✔ Reduces duplicate logic
✔ Makes systems flexible
✔ Perfect for plug-and-play behaviour

---

💡 When Is Polymorphism Useful?

Whenever you have:

• Multiple objects sharing an action
• Each object needs its own version of that action
• You want to simplify function calls

Examples:

• Notifications (email, SMS, push)
• Rendering UI widgets
• Payment gateways
• Vehicles / animals / game characters
• API handlers

---

🏁 Final Thoughts

Polymorphism is not as scary as it sounds.
It’s simply:

“Same method name, different behavior.”

Once you understand this idea, JavaScript classes feel more intuitive, flexible, and clean.

Use it to build smarter, more scalable apps!