When to select Design Pattern

Choosing the correct design pattern in software engineering is critical to practical problem-solving. This post will try to simplify the process, helping you decide between patterns based on specific needs.

To select a pattern, we must first go through the problem identification. If the problem is related to:

• Object Creation? - Creational Patterns

• Object Assembly? - Structural Patterns

• Object Interections? - Behavioral Patterns

1. Singleton: Ensures only one instance exists.

2. Factory Method: Delegates object instantiation to subclasses.

3. Abstract Factory: Creates related object families without specifying their concrete classes.

4. Prototype: Clones objects for a prototypical instance.

5. Builder: Constructs complex objects step by step.

6. Adapter: Bridges incompatible interfaces.

7. Bridge: Separates abstraction from implementation.

8. Composite: Treats single and composite objects uniformly.

9. Decorator: Adds behaviors to objects dynamically.

10. Facade: Simplifies complex system interfaces.

11. Flyweight: Shares objects to reduce memory.

12. Proxy: Controls object access.

13. Observer: Notifies changes to multiple objects.

14. Strategy: Encapsulates interchangeable algorithms.

15. Command: Encapsulates a request as an object.

16. State: Changes object behavior with internal state.

17. Visitor: Adds operations to object structures without modifying them.

18. Memento: Captures and restores object states externally.

19. Iterator: Sequentially accesses elements of a collection.

20. Mediator: Centralizes complex communications.

21. Chain of Responsibility: Passes requests along a chain of handlers.

22. Template Method: Defines the skeleton of an algorithm.