Design Patterns

This repository contains Design Patterns as discussed in the book Head First Design Patterns

Video Reference: Design Patterns in Object Oriented Programming

Patterns

1. Strategy Pattern
2. Observer Pattern
3. Decorator Pattern
4. Factory Pattern
5. Singleton Pattern
6. Abstract Factory Pattern
7. Command Pattern
8. Adapter Pattern
9. Facade Pattern
10. Proxy Pattern

OO Principles

• Encapsulate what varies.
• Favour Composition over Inheritence
• Program to interfaces not implementations.
• Strive for loosly coupled designs between objects that interact.
• Classes should be open for extension but closed for modification.
• Depend on abstractions. Do not depend on concrete classes.
• Principle of Least Knowledge: talk only to your immediate friends (Reduces Dependencies)