This repo contains the notes and sample codes I generated while learning about software design patterns using the book Head First Design Patterns.

1. Strategy / Policy
2. Observer
3. Decorator
4. Factory
5. Singleton
6. Command

1. Identify the aspects of your application that vary and separate them from what stays the same.
2. Program to an interface, not an implementation.
3. Favor composition over inheritance.
4. Strive for loosely coupled designs between objects that interact.
5. Classes should be open for extension, but closed for modification.
6. Depend upon abstractions. Do not depend upon concrete classes.