Design patterns

Principles:

• Code for interface and not for implementation
• Prefer object composition over inheritence 

Types of Design Patterns

1. Creational Design Patterns

• Singleton
• Factory 
• Abstract factory
• Builder
• prototype

2. Structural Design Pattern

• Adapter
• Composite
• Proxy
• Fly weight
• Facade
• Bridge
• Decorator 

3. Behavioral Design Patterns

• Template method
• Mediator
• Chain of responsibility
• Observer
• Strategy
• Command
• State
• Visitor
• Iterator
• Interpreter
• memento