Programare Orientată pe Obiecte

Overview of the five principles for maintainable, scalable object-oriented design

A class should have one, and only one, reason to change

Software entities should be open for extension but closed for modification

Objects of a superclass should be replaceable with objects of its subclasses without affecting program correctness

Clients should not be forced to depend on interfaces they do not use

High-level modules should not depend on low-level modules; both should depend on abstractions