23 GoF Patterns

Master Design Patterns

Learn all 23 Gang of Four design patterns with clear examples, diagrams, and real-world code.

23 Patterns

3 Categories

5 Code Languages

2 UI Languages

Object creation mechanisms for flexible, reusable code.

Compose objects into larger, flexible structures.

Efficient communication and responsibility between objects.

Lets any number of objects subscribe to and get notified about another object's changes.

Guarantees a class has exactly one instance and gives the whole program one way to reach it.

Packages interchangeable algorithms into their own classes so they can be swapped at runtime.

Adds new behavior to a single object by wrapping it in layers that share its interface.

Delegates object creation to a method subclasses can override, hiding the exact type being built.

Hides a tangle of interacting classes behind one simple entry point.

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