Design Patterns Overview

Hello everyone!

Often, teams deliver solutions lacking maintainability, scalability, and reusability. Design patterns are crucial in software engineering as they encapsulate best practices, enhance communication, improve code quality, and promote reusability and maintainability. By understanding and applying design patterns, developers can create robust, scalable, and efficient software systems.

These patterns are proven solutions to common design problems, refined through the experience of skilled developers. Here’s an overview of what design patterns are and some common examples:

What are Design Patterns?

• Definition: Design patterns are reusable solutions to common problems in software design. They are templates that can be applied to real-world programming situations.

• Purpose: Improves code readability and reusability. They provide a shared language for developers to communicate about design solutions.

• Categories:

  • Creational Patterns: Deals with object creation mechanisms
  • Structural Patterns: Deals with object composition and typically identify simple ways to realize relationships between different objects.
  • Behavioral Patterns: Deal with object interaction and responsibility.

Common Design Patterns

Creational Patterns:

• Singleton Method: Ensures a class has only one instance and provides a global point of access to it.

• Factory Method: Defines an interface for creating an object but lets subclasses alter the type of objects that will be created.

• Abstract Factory Method: Provides an interface for creating families of related or dependent objects without specifying their concrete classes.

• Builder Method: Separates the construction of a complex object from its representation, allowing the same construction process to create various representations.

• Prototype Method: Specifies the kinds of objects to create using a prototypical instance and creates objects by copying this prototype.

Structural Patterns:

• Adapter: Allows incompatible interfaces to work together.
• Bridge: Separates an object’s interface from its implementation, allowing the two to vary independently.
• Composite: Composes objects into tree structures to represent part-whole hierarchies.
• Decorator: Adds additional responsibilities to an object dynamically.
• Facade: Provides a simplified interface to a complex subsystem.
• Flyweight: Reduces the cost of creating and manipulating a large number of similar objects.
• Proxy: Provides a surrogate or placeholder for another object to control access to it.

Behavioral Patterns:

• Chain of Responsibility: Passes a request along a chain of handlers.
• Command: Encapsulates a request as an object, thereby allowing for parameterization of clients with queues, requests, and operations.
• Interpreter: Implements a specialized language.
• Iterator: Provides a way to access elements of a collection sequentially without exposing its underlying representation.
• Mediator: Reduces the coupling between classes by restricting direct communications between objects and forcing them to communicate via a mediator.
• Memento: Captures and externalizes an object’s internal state so that the object can be restored to this state later.
• Observer: Defines a one-to-many dependency between objects so that when one object changes state, all its dependents are notified.
• 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, deferring some steps to subclasses.
• Visitor: Represents an operation to be performed on elements of an object structure.

Benefits of Using Design Patterns

• Efficiency: Save time and avoid errors by using proven solutions.
• Reusability: Enhance code reuse and reduce redundancy.
• Maintainability: Improve code readability and maintainability.
• Scalability: Provide solutions that scale with the application’s growth.
• Communication: Establish a common language for discussing design decisions.

By applying design patterns, developers can create more robust and maintainable software systems.

We’ll go over each of these with examples in future posts.

Cheers :)