Design Patterns: Prototype and Abstract Factory

Prototype Pattern

• Prototype pattern allows developers to clone pre-configured objects instead of creating them from scratch.
• Prototype interface defines the cloning methods (usually a single clone() method).
• Concrete Prototype class implements the clone() method to copy the original object's data and handle any edge cases of the cloning process.
• Client class can create a copy of any object that follows the prototype interface.
• Prototype Registry provides easy access to frequently used prototypes by storing them and their copies.

Abstract Factory Pattern

• Abstract Factory pattern enables the creation of families of related objects without specifying their concrete classes.
• Example: A furniture shop simulator with different furniture families like modern, art deco, and Victorian, allowing the creation of objects within each family.
• The pattern prevents code repetition by providing a way to get instances of particular families without having to know the specific product types.

Decorator Pattern

• Decorator pattern lets developers customize existing objects dynamically by adding new functionalities through wrappers.
• The pattern allows for extending an object's behavior at runtime and wrapping multiple decorators around a single object.
• The wrapper object has the same methods as the target object and delegates requests to the wrapped object while adding additional behaviors.
• Example: Adding notification functionality to a base Notifier object using decorators, each decorator extending the functionality.

Facade Pattern

• Facade pattern provides a simplified interface for accessing a complex subsystem. It hides the complexity of the subsystem behind a single unified interface.
• Simplifies the interaction with the subsystem for clients.
• Example: A facade for a complex payment system, allowing clients to interact with it through a single interface.

Flyweight Pattern

• Flyweight Pattern aims to decrease memory usage by sharing common data between multiple objects.
• It separates object data into intrinsic and extrinsic states.
• Intrinsic state remains constant and is shared among objects. Extrinsic state is unique to each object and passed to the flyweight object when needed.
• Example: In a video game, particle system objects can share color and sprite information, while individual particles have unique coordinates, movement, and speed.

Iterator Pattern

• Iterator pattern provides a consistent way to traverse a collection object without revealing its internal structure.
• Iterator interface defines methods for traversing a collection.
• Concrete Iterator class implements the traversal logic for a specific collection type.
• Client works with collection and iterators through their interfaces, enabling flexibility and adaptability to different collections.

Observer Pattern

• Observer pattern defines a one-to-many dependency between objects, allowing multiple observers to receive updates from a single object.
• Publisher object notifies its subscribers about changes in its state.
• Subscribers implement a notification interface and receive updates from the publisher.
• Example: A store (publisher) notifies customers (subscribers) about new products, allowing them to subscribe to updates and receive notifications.

This quiz covers the Prototype and Abstract Factory design patterns, key concepts in object-oriented programming. Learn about how these patterns allow for object creation and management without the need for concrete class specifications. Test your understanding of cloning objects and creating families of related objects with this quiz.