An introduction design patterns. Covers the idea behind design patterns, classification, origin, and objectives.

1. Design Patterns
from
10K feet
Naresha K.
naresha.k@gmail.com
@naresha_k

2. Solution to common problems
in a context

3. Designing object-oriented software is hard.
Designing reusable OO software is even
harder.

5. Each pattern describes a problem which
occurs over and over again in our
environment, and then describes the core of
the solution to that problem, in such a way that
you can use this solution a million times over
without ever doing it in the same way twice.
- Christopher Alexander

6. Elements of Design Patterns
• Pattern name
• Problem
• Solution
• Consequences

7. Classifications
• Creational
• Structural
• Behavioural

8. Creational
• Patterns that help you to create an instances of objects

9. Structural
• Help you to organise (structure) classes or objects

10. Behavioural
• Help you to distribute responsibilities among objects

11. Wisdom #1
Program to an interface, not an
implementation

12. Wisdom #2
Encapsulate what changes

13. Wisdom #3
Favour composition to inheritance

14. Creational Patterns
• Abstract Factory
• Builder
• Factory Method
• Prototype
• Singleton

15. Structural Patterns
• Adapter
• Bridge
• Composite
• Decorator
• Facade
• Flyweight
• Proxy

16. Behavioural Patterns
• Chain of Responsibility
• Command
• Interpreter
• Iterator
• Mediator
• Memento
• Observer
• State
• Strategy
• Template Method
• Visitor