Object Oriented Design ↩
The goal of programming models is to improve the management of large software systems.
1. Structured Programming
Languages : ALGOL, Pascal, Ada
3 control statements : Sequence, Selection, Iteration
2. Aspect Oriented Programming (AOP)
Refer ↗ for basic concept.
3. Object Oriented Design (OOD)
5 Principles of Class Design - SOLID
Single Responsibility: Every class should have only one responsiblity (only one reason to change).Open-closed: Open for extension, closed for modification.Liskov Substituition: Derived classes must be substitutable for their base classes. Clients that use pointers to base classes must be able to use objects of the derived classes without knowing it.Interface Segregation: Clients shouldn’t need to depend upon interfaces that they don’t use. Make interface fine-grained and client-specific.Dependancy Inversion: Use abstractions, promote loose coupling.
Loose coupling is an approach to interconnecting the components in a system, network or software application so that those components, also called elements, depend on each other to the least extent practicable. Coupling refers to the degree of direct knowledge that one element has of another.
Class relationships
Software contracts exist to promote componentization to develop independently and concurrently. This is implemeneted via interfaces.
Example:
User interface <-> Communication interface <-> Networking.
The contract merely includes SEND and RECEIVE.