Types of Design Patterns

Design patterns are reusable solutions to commonly occurring problems in software design. They provide a way to share best practices and improve the quality and maintainability of code.

Creational Patterns

Factory Method: Defines an interface for creating an object, but lets subclasses decide which class to instantiate.
Abstract Factory: Provides an interface for creating families of related objects without specifying their concrete classes.
Singleton: Ensures that only one instance of a class is created.
Builder: Separates the construction of a complex object from its representation, allowing for different representations to be built from the same construction process.
Prototype: Creates new objects by copying an existing object.

Structural Patterns

Adapter: Converts the interface of a class into another interface clients expect.
Bridge: Decouples an abstraction from its implementation, allowing them to be changed independently.
Composite: Composes objects into tree structures to represent part-whole hierarchies.
Decorator: Attaches additional responsibilities to an object dynamically without changing its structure.
Facade: Provides a unified interface to a set of subroutines.
Flyweight: Reduces the number of objects in a program by sharing common objects.
Proxy: Provides a surrogate or placeholder for another object to control access to it.

Behavioral Patterns

Chain of Responsibility: Passes requests along a chain of objects to give multiple objects the opportunity to handle it.
Command: Encapsulates a request as an object, allowing clients to parameterize, queue, and undo requests.
Interpreter: Defines a grammar for interpreting a language and provides an interpreter to execute the grammar.
Iterator: Provides a way to access the elements of an object sequentially without exposing the underlying representation.
Mediator: Defines an object that encapsulates how a set of objects interact.
Observer: Defines a one-to-many dependency between objects, so that when one object changes state, all its dependents are notified and updated automatically.
State: Allows an object to alter its behavior when its internal state changes.
Strategy: Defines a family of algorithms, encapsulates each one, and makes them interchangeable.
Template Method: Defines the skeleton of an algorithm in a method, deferring some steps to subclasses.
Visitor: Allows an operation to be performed on the elements of an object structure without changing the structure itself.