Factory

In Factory Design Pattern we create an object without exposing the object creation and initialization logic to the client and client will refer to the newly created object using a common interface

Overview

The Factory pattern is a creational design pattern that provides an interface for creating objects without specifying their exact classes. It encapsulates object creation logic and returns objects through a common interface.

Implementation Details

This implementation demonstrates a credit card system where different types of credit cards are created based on client requirements:

Key Components:

• ICreditCard Interface: Common interface for all credit card types
• CreditCardFactory: Factory class that creates appropriate credit card objects
• Concrete Products: MoneyBack, Platinum, and Titanium credit card implementations

Classes:

• ICreditCard - Product interface defining GetCardType(), GetCreditLimit(), and GetAnnualCharge() methods
• CreditCardFactory - Factory class with static GetCreditCard() method
• MoneyBack - Concrete product with basic features (₹1500 limit, ₹500 annual charge)
• Platinum - Concrete product with premium features (₹35000 limit, ₹2000 annual charge)
• Titanium - Concrete product with mid-tier features (₹25000 limit, ₹1500 annual charge)

Usage Example:

ICreditCard cardDetails = CreditCardFactory.GetCreditCard("Platinum");

if (cardDetails != null)
{
    Console.WriteLine("CardType: " + cardDetails.GetCardType());        // "Platinum Plus"
    Console.WriteLine("CreditLimit: " + cardDetails.GetCreditLimit());   // 35000
    Console.WriteLine("AnnualCharge: " + cardDetails.GetAnnualCharge()); // 2000
}

Benefits:

• Encapsulates object creation logic in one place
• Client code doesn't need to know about concrete classes
• Easy to add new credit card types without modifying existing code
• Follows Single Responsibility Principle
• Reduces coupling between client and concrete classes