The document discusses the principles of object-oriented programming (OOP) concepts and their applications in software development, focusing on functionality, analysis, and design patterns. It outlines key OOP concepts such as inheritance, polymorphism, encapsulation, and composition, and explains their importance in creating maintainable and scalable solutions. Additionally, it introduces the Unified Modeling Language (UML) as a way to represent system functionality through various diagrams, including use-case and class diagrams.

1. Object Oriented Programming Concepts Analysis + Design

2. What’s in store… Real world problems  software solution Functionality – Requirements/Use-cases Object Oriented [OO] Concepts Unified Modeling Language [UML] Simple Design Pattern

3. Real World Problems  Software Solutions 1. Functionality - The code should do what it’s supposed to do 2. Analysis and Design - Application of basic OO concepts 3 . Frameworks & Design Patterns – Strive for a maintainable and scalable solution

4. Functionality – Requirements & Use-cases Requirements set out the final expectations from the system Use-case enumerates in detail the steps the system should take Use-case has a single goal Every use-case has a start and stop condition, an external initiator and clear value

5. Functionality – Requirements & Use-cases A B C … UC 1 UC 2 UC 4 UC2 UC3 UC4 UC1 UC4 UC5 UC6 Requirements

6. OO Concepts Everything is an Object Everything consists of objects

7. OO Concepts – I N H E R I T A N C E Build classes based on other classes Avoid duplicating and repeating Inherit behaviour and change [ override ] if required Sub-class should be substitutable for parent class

8. OO Concepts – P O L Y M O R P H I S M Change behaviour without changing code Allows a sub-class to stand-in for another class

9. OO Concepts – E N C A P S U L A T I O N Protect information in your code from being used incorrectly Object = state + behaviour Also known as Information Hiding or Separation of Concerns Duplicate code is an indicator

10. OO Concepts – C O M P O S I T I O N Loose coupling between objects Greater flexibility Code changes don’t lead to cascading code breakage Better encapsulation

11. Unified Modeling Language – U M L Purely representational Programming language independent A notational set based language and NOT a methodology Fits easily into any company’s way of functioning Conveys information through a wide set of diagrams Use-case diagram Class diagram Sequence diagram State-chart diagram Activity diagram Component diagram

12. U M L – Use-Case Diagram Illustrates a unit of functionality Helps visualize functional requirements of a system Include relationships of actors [users] to processes

13. U M L – Class Diagram Shows the static structures and relationships of a system Can be used to display logical groupings/classifications Also used to depict implementation classes Both the state and behaviour of classes captured Relationships between classes also important

14. U M L – Sequence Diagram Depicts in detail the flow of control through a use-case Consists of 2 dimensions – Horizontal – shows sequence of calls/messages in time order of occurrence Vertical – the object instances to which messages are sent Sequence of flow starts at the top left corner

15. A Design Pattern – D E L E G A T I O N An object outwardly exhibits a behaviour – which is performed by another object Better encapsulation Impact of code changes minimised Sometimes referred to as aggregation Example – A stack built on top of a list

16. So, WHAT MAKES GOOD CODE?

17. References UML Basic: An Introduction [IBM] Head First - Object Oriented Analysis and Design Wikipedia