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Software Design Patterns: Gang of Four, Catalogs & Code Examples

The Gang of Four patterns and beyond: catalogs, code examples in many languages, design principles, anti-patterns, books and communities.

34 topics•5 categories•Updated October 2026

Pattern Catalogs

12 entries

Online catalogs of design patterns with diagrams and examples.

01Refactoring Guru: Design PatternsIllustrated explanations of the 22 classic patterns with code in several languages. 02Refactoring Guru: CatalogCatalog grouped into creational, structural and behavioral patterns. 03SourceMaking: Design PatternsPattern catalog with refactoring and anti-pattern sections. 04Software design pattern (Wikipedia)Overview of design pattern history and categories. 05Design Patterns, the book (Wikipedia)Article on the Gang of Four book and its 23 patterns. 06A Pattern Language (Wikipedia)Christopher Alexander's architecture book that inspired software patterns. 07Dofactory: .NET Design PatternsC# examples of the Gang of Four patterns. 08Baeldung: Design Patterns SeriesJava-focused pattern tutorials; the site blocks automated checks. 09GeeksforGeeks: Software Design PatternsTutorial overview of design patterns. 10Patterns.devDesign, rendering and performance patterns for JavaScript and React. 11Game Programming PatternsFree book on patterns for game code. 12Rust Design PatternsCatalog of idioms, patterns and anti-patterns for Rust.

Code Examples on GitHub

5 entries

Runnable examples in different languages.

13python-patternsDesign patterns implemented in Python. 14java-design-patternsDesign patterns implemented in Java. 15go-patternsCurated Go design patterns and idioms. The GitHub repository's last commit was in July 2017, so check its activity before relying on it. 16Design Patterns for HumansPlain-language explanations of design patterns; the original kamranahmedse address redirects here. The repository's last commit was in December 2024, so check its activity. 17Awesome Design PatternsCurated list of design pattern and software architecture resources. The GitHub repository's last commit was in October 2024, so check its activity before relying on it.

Principles, Anti-patterns & Refactoring

5 entries

Guidelines that patterns support.

18SOLID (Wikipedia)Five object-oriented design principles. 19Anti-pattern (Wikipedia)Common responses to recurring problems that turn out ineffective. 20Inversion of Control Containers and the Dependency Injection pattern (Fowler)Fowler's classic article on dependency injection. 21Is Design Dead? (Fowler)Essay on design in agile development. 22Dependency Injection Principles, Practices, and Patterns (Manning)Book on dependency injection.

Books & Communities

5 entries

Where patterns are written and discussed.

23Design Patterns: Elements of Reusable Object-Oriented Software (InformIT)The Gang of Four book by Gamma, Helm, Johnson and Vlissides. 24Design Patterns (O'Reilly)The Gang of Four book on O'Reilly; the site blocks automated checks. 25Head First Design Patterns (O'Reilly)Visual introduction to design patterns. 26Hillside GroupNon-profit that fosters the patterns community. 27PLoP conferences (Hillside)Pattern Languages of Programs conference series.

Related Pages

7 entries

Neighbouring pages on this site.

28Software Architecture PatternsArchitecture-level pattern catalog. 29Architecture Patterns HubArchitecture styles hub. 30Microservices Design PatternsSaga, API gateway, CQRS and more. 31Event-Driven Architecture Design PatternsEvent-driven patterns. 32JavaJava resources. 33Static Code Analysis ToolsStatic analysis tools. 34Software EngineeringSoftware engineering hub.

Frequently Asked Questions

What are software design patterns?

Design patterns are reusable solutions to common, recurring problems in object-oriented and other software design, described by a name, a problem, a solution and its trade-offs.

What are the Gang of Four patterns?

The 1994 book Design Patterns by Gamma, Helm, Johnson and Vlissides catalogs 23 patterns in three groups: creational (such as Factory and Singleton), structural (such as Adapter and Decorator) and behavioral (such as Observer and Strategy).

When should I not use a pattern?

Patterns can add needless complexity when a simpler design works; use them to solve a real problem, not as a goal. Anti-patterns describe common misuses.

Where can I see code examples?

Refactoring Guru has examples in several languages, and GitHub repositories such as python-patterns and java-design-patterns offer runnable code.

How current is this page?

Links were checked in October 2026. Sites that block automated checks (O'Reilly and Baeldung) are kept and may need a manual click. Pattern names and definitions vary between authors, so treat each catalog as one perspective.