Heads Up Design Patters

Heads Up Design Patterns book exercises.

SymUDuck

Strategy pattern

Defines a family of algorithms, encapsulates each one, and makes them interchangeable. Strategy lets the algorithm vary independently from clients that use it.

Weather-O-Rama

Observer

Defines a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically

OO Basics

• Abstraction
• Encapsulation
• Polymorphism
• Inheritance

OO Principles:

• Encapsulate what varies.
• Favor composition over inheritance.
• Program to interfaces, not implementations.
• Strive for loosely coupled designs between objects that interact.
• Classes should be open for extension, but closed for modification