How does OCP relate to interfaces and abstract classes?

• Interfaces and abstract classes provide a contract that other classes can

implement or inherit.

• They enable polymorphism, which allows behavior to be extended without altering

existing code.

• By programming to abstractions (not concrete implementations), you can easily

introduce new behavior (via new implementations) while keeping the core logic

unchanged.

✅ OCP encourages extending via new subclasses or interface implementations, not

modifying existing ones.

Liskov Substitution Principle (LSP)