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Design Patterns 101

Principles

1) Program to an interface rather than an implementation.

2)  Composition and delegation result in runtime flexibility and should be favored to inheritance.

3) Find out what varies and encapsulate it.

Types of Patterns

:: Creational (factory, prototype, singleton)

:: Structural (adapter, proxy, façade)

:: Behavioral ( State, Visitor, Template Method, Strategy)

Notes

- Good when used correctly

- Bad when used like hammer with no nails