Mastering the GoF Design Patterns: Explained with Modern Examples
The Gang of Four (GoF) design patterns are the foundational building blocks of software architecture. Introduced in the landmark book “Design Patterns: Elements of Reusable Object-Oriented Software”*, these 23 patterns help developers solve common design problems with proven solutions.
In this guide, you’ll find modern explanations, practical C# examples, and links to in-depth tutorials for each pattern.
🧩 What Are GoF Design Patterns?
GoF patterns are categorized into three main groups:
- Creational Patterns – How objects are created
- Structural Patterns – How objects are composed
- Behavioral Patterns – How objects communicate
Each category solves a specific set of design challenges. Scroll down to find pattern summaries and deep dives into each one.
🧱 Creational Patterns
These patterns abstract the object creation process and help manage flexibility and reuse.
Pattern | Description | Link |
|---|---|---|
Singleton | Ensure a class has only one instance | Explore the Singleton Pattern → |
Factory Method | Delegate instantiation to subclasses | Understand the Factory Method Pattern → |
Abstract Factory | Create families of related objects | Dive into the Abstract Factory Pattern → |
Builder | Construct complex objects step by step | Learn how the Builder Pattern works → |
Prototype | Clone existing objects without coupling | Explore the Prototype Pattern in C# → |
🧱 Structural Patterns
These patterns abstract the object creation process and help manage flexibility and reuse.
Pattern | Description | Link |
|---|---|---|
Adapter | Convert one interface into another | See the Adapter Pattern in Action → |
Bridge | Separate abstraction from implementation | Bridge Pattern Explained with Examples → |
Composite | Treat individual and grouped objects uniformly | Discover the Composite Pattern → |
Decorator | Add responsibilities to objects dynamically | How the Decorator Pattern Extends Behavior → |
Facade | Simplify complex subsystems with a unified interface | Understand the Facade Pattern → |
Proxy | Control access to objects | Explore the Proxy Pattern in Practice → |
🧱 Behavioral Patterns
These patterns abstract the object creation process and help manage flexibility and reuse.
Pattern | Description | Link |
|---|---|---|
Chain of Responsibility | Pass requests along a chain of handlers | Handle Requests with Chain of Responsibility → |
Command | Encapsulate requests as objects | How the Command Pattern Works → |
Iterator | Access elements without exposing structure | Implement Iterators the Right Way → |
Mediator | Centralize complex communications | Simplify Communication with Mediator Pattern → |
Memento | Save and restore object state | Preserve State Using Memento Pattern → |
Observer | Notify objects of state changes | Master the Observer Pattern → |
State | Change behavior based on internal state | Manage State with the State Pattern → |
Strategy | Define interchangeable algorithms | Switch Logic with the Strategy Pattern → |
Template Method | Define the skeleton of an algorithm | Use the Template Method Pattern → |
Visitor | Add new operations to existing structures | Visitor Pattern Made Simple → |
🧭 Beyond GoF Patterns: What to Learn Next
Understanding the 23 Gang of Four design patterns gives you a strong foundation in software design. But modern software development also requires mastery of architecture patterns, SOLID principles, and real-world implementation strategies.
Here’s where to continue:
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🔹 Clean Architecture Principles →
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🔹 Mastering SOLID Principles →
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🔹 Modern Architecture Patterns (Microservices, DDD) →
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🔹 How to Use Design Patterns in Real Projects →