Design Patterns

Learn

Existing chapters for this concept.

• Design Patterns

  Patterns

  For each of the 23 patterns in : 1. Run the demo 2. Draw a class diagram on paper 3.

  Open lesson →

See it in code

Existing Java examples.

• patterns 10 Facade Pattern

  Design patterns · pkg8patterns/patterns10FacadePattern.java · pkg8patterns · patterns10FacadePattern.java

  Open example →
• patterns 11 Flyweight Pattern

  Design patterns · pkg8patterns/patterns11FlyweightPattern.java · pkg8patterns · patterns11FlyweightPattern.java

  Open example →
• patterns 12 Proxy Pattern

  Design patterns · pkg8patterns/patterns12ProxyPattern.java · pkg8patterns · patterns12ProxyPattern.java

  Open example →
• patterns 13 Chain Of Responsibility Pattern

  Design patterns · pkg8patterns/patterns13ChainOfResponsibilityPattern.java · pkg8patterns · patterns13ChainOfResponsibilityPattern.java

  Open example →
• patterns 14 Command Pattern

  Design patterns · pkg8patterns/patterns14CommandPattern.java · pkg8patterns · patterns14CommandPattern.java

  Open example →
• patterns 15 Interpreter Pattern

  Design patterns · pkg8patterns/patterns15InterpreterPattern.java · pkg8patterns · patterns15InterpreterPattern.java

  Open example →
• patterns 16 Iterator Pattern

  Design patterns · pkg8patterns/patterns16IteratorPattern.java · pkg8patterns · patterns16IteratorPattern.java

  Open example →
• patterns 17 Mediator Pattern

  Design patterns · pkg8patterns/patterns17MediatorPattern.java · pkg8patterns · patterns17MediatorPattern.java

  Open example →
• patterns 18 Memento Pattern

  Design patterns · pkg8patterns/patterns18MementoPattern.java · pkg8patterns · patterns18MementoPattern.java

  Open example →
• patterns 19 Observer Pattern

  Design patterns · pkg8patterns/patterns19ObserverPattern.java · pkg8patterns · patterns19ObserverPattern.java

  Open example →
• patterns 1 Singleton Pattern

  Design patterns · pkg8patterns/patterns1SingletonPattern.java · pkg8patterns · patterns1SingletonPattern.java

  Open example →
• patterns 20 State Pattern

  Design patterns · pkg8patterns/patterns20StatePattern.java · pkg8patterns · patterns20StatePattern.java

  Open example →
• patterns 21 Strategy Pattern

  Design patterns · pkg8patterns/patterns21StrategyPattern.java · pkg8patterns · patterns21StrategyPattern.java

  Open example →
• patterns 22 Template Method Pattern

  Design patterns · pkg8patterns/patterns22TemplateMethodPattern.java · pkg8patterns · patterns22TemplateMethodPattern.java

  Open example →
• patterns 23 Visitor Pattern

  Design patterns · pkg8patterns/patterns23VisitorPattern.java · pkg8patterns · patterns23VisitorPattern.java

  Open example →
• patterns 2 Factory Method Pattern

  Design patterns · pkg8patterns/patterns2FactoryMethodPattern.java · pkg8patterns · patterns2FactoryMethodPattern.java

  Open example →
• patterns 3 Abstract Factory Pattern

  Design patterns · pkg8patterns/patterns3AbstractFactoryPattern.java · pkg8patterns · patterns3AbstractFactoryPattern.java

  Open example →
• patterns 4 Builder Pattern

  Design patterns · pkg8patterns/patterns4BuilderPattern.java · pkg8patterns · patterns4BuilderPattern.java

  Open example →
• patterns 5 Prototype Pattern

  Design patterns · pkg8patterns/patterns5PrototypePattern.java · pkg8patterns · patterns5PrototypePattern.java

  Open example →
• patterns 6 Adapter Pattern

  Design patterns · pkg8patterns/patterns6AdapterPattern.java · pkg8patterns · patterns6AdapterPattern.java

  Open example →
• patterns 7 Bridge Pattern

  Design patterns · pkg8patterns/patterns7BridgePattern.java · pkg8patterns · patterns7BridgePattern.java

  Open example →
• patterns 8 Composite Pattern

  Design patterns · pkg8patterns/patterns8CompositePattern.java · pkg8patterns · patterns8CompositePattern.java

  Open example →
• patterns 9 Decorator Pattern

  Design patterns · pkg8patterns/patterns9DecoratorPattern.java · pkg8patterns · patterns9DecoratorPattern.java

  Open example →

Reference

• Design Patterns (GoF)

  Reference

  Runnable examples: . Each file documents intent, UML, pros, cons, and a real-world use .

  Open reference →

Prepare

Existing interview questions.

• Design Patterns (GoF) — Interview Questions (80+)

  Design Patterns (GoF) — Interview Questions (80+)

  Match the problem; prefer the simplest solution that communicates intent.

  Open question →
• OOP & SOLID Design — Interview Questions (95+)

  OOP & SOLID Design — Interview Questions (95+)

  Patterns often implement SOLID goals.

  Open question →