Introduction to DSA

🔹 Factory Design Pattern

The **Factory Design Pattern** is a **creational pattern** that provides an interface for creating objects in a superclass while allowing subclasses to alter the type of objects that will be created.

📌 Why Use the Factory Pattern?

The Factory Pattern is useful for **decoupling object creation** from its implementation.

✅ **Encapsulation of Object Creation** – Hides complex instantiation logic.
✅ **Improves Maintainability** – Easy to add new object types without modifying existing code.
✅ **Supports Open-Closed Principle** – New classes can be introduced without altering existing code.

💡 Real-Life Example

Consider a **Vehicle Factory** that produces different types of vehicles (Car, Bike) without exposing the instantiation details.

🖥️ Factory Pattern in Java

In Java, we implement the Factory Pattern using a **factory method**.


            interface Vehicle {
                void drive();
            }
            
            class Car implements Vehicle {
                public void drive() {
                    System.out.println("Driving a Car.");
                }
            }
            
            class Bike implements Vehicle {
                public void drive() {
                    System.out.println("Riding a Bike.");
                }
            }
            
            class VehicleFactory {
                public static Vehicle getVehicle(String type) {
                    if (type.equalsIgnoreCase("Car")) {
                        return new Car();
                    } else if (type.equalsIgnoreCase("Bike")) {
                        return new Bike();
                    }
                    return null;
                }
            }
            
            public class Main {
                public static void main(String[] args) {
                    Vehicle car = VehicleFactory.getVehicle("Car");
                    car.drive();
                }
            }

🖥️ Factory Pattern in Python

In Python, we use a function to implement the **Factory Pattern**.


            class Car:
                def drive(self):
                    print("Driving a Car.")
            
            class Bike:
                def drive(self):
                    print("Riding a Bike.")
            
            class VehicleFactory:
                @staticmethod
                def get_vehicle(vehicle_type):
                    if vehicle_type.lower() == "car":
                        return Car()
                    elif vehicle_type.lower() == "bike":
                        return Bike()
                    return None
            
            vehicle = VehicleFactory.get_vehicle("car")
            vehicle.drive()

🎯 Summary