The Null Object pattern is a behavioral design pattern that provides a default object as a representative of "null" in the context of design patterns.

Command pattern is a design pattern that converts a request into a standalone object, allowing the client to parametrize objects with different requests, queue a request, or log requests. The pattern involves creating a command class that encapsulates the request as an object, and passes the request to the invoker object. The invoker object then executes the command. This pattern can be useful in situations where you want to decouple the client from the receiver of the request, and where you want to provide a unified interface for undo and redo operations.

The State pattern allows an object to alter its behavior when its internal state changes, while the Strategy pattern allows an object to change its behavior based on the context it is in

A behavioral design pattern that separates an algorithm from an object structure on which it operates. The pattern allows you to define a new operation without changing the classes of the objects on which it operates.

Inversion of Control is a design principle in which the flow of control in a system is inverted. Instead of a system calling components to perform tasks, components are notified when tasks are ready and perform them. This leads to a more flexible and decoupled system, allowing for easier maintenance and testing.

The actor classes used in the Memento pattern are: Originator, Memento, and Caretaker. The Originator class is responsible for creating the memento and restoring its state. The Memento class is responsible for storing the internal state of the Originator. The Caretaker class is responsible for maintaining a list of mementos and providing the Originator with the appropriate memento at the appropriate time.

One example of where Interpreter pattern is used is in compilers, where expressions in a programming language need to be parsed and evaluated. The Interpreter pattern can be used to evaluate the syntax and semantics of a programming language, and generate code or perform other actions based on the results of the evaluation.

CQRS is a pattern that separates the responsibilities of querying data (read) from modifying data (write) into separate models, improving scalability and maintainability of the application.

The Null Object pattern is a design pattern in which a special object, called the null object, is used to represent the absence of a value, avoiding the need for explicit checks for null values. The Null Object pattern is used to provide a default implementation of an interface, reducing the amount of error-prone null checks in the code. The Null Object pattern can also be used to simplify the code and reduce coupling by eliminating the need for explicit checks for null values.

Prototype pattern is a design pattern that creates objects by cloning existing objects, rather than creating new instances from scratch. This pattern involves implementing a prototype interface, which is used to create a new instance of the object. The new instance is a copy of the existing object, with any changes made to the copy not affecting the original.