Applying Creational Patterns in Banking System

Welcome to the unit of this course! In previous lessons, we've explored various creational design patterns such as the Singleton, Factory Method, Abstract Factory, and Builder patterns. Before diving into our practical example of a banking system, let's take a moment to recap these patterns and understand their importance.

Creational patterns are design patterns that deal with object creation mechanisms, trying to create objects in a manner suitable to the situation. They help make a system independent of how its objects are created, composed, and represented. These patterns are essential for designing robust, maintainable, and scalable applications. Here are the primary benefits of using creational patterns:

1. Maintainability: They help organize code in a structured manner, making it easier to maintain and extend.
2. Flexibility: These patterns promote using interfaces and abstract classes, allowing the substitution of specific implementations without changing existing code.
3. Reusability: By isolating instantiation logic, these patterns make it easier to reuse code across different parts of an application or even different projects.

Let's quickly recap all of the Creational Patterns we've covered so far.

The Singleton pattern ensures a class has only one instance and provides a global point of access to it. This is particularly useful for shared resources like configuration settings or logging, where having multiple instances could lead to inconsistent states. In the context of a banking system, a Singleton could be used to manage the logging system, ensuring all actions are recorded consistently.

The Factory Method pattern defines an interface for creating an object but allows subclasses to alter the type of objects that will be created. This pattern helps in adhering to the SOLID principles by reducing the dependency on concrete classes. For instance, in a banking system, a Factory Method can be used to create different types of accounts (Savings, Current) without changing the existing instantiation logic.