In this presentation I will explain the principles of OO design with the help of Freddy Nostrils and his Illegal Muppet trade.

1. Object Oriented Design Principles with silly names but help you code more betterer.

2. SOLID

3. FREDDY NOSTRILS

4. Illegal Muppets

5. 1. Single Responsibility Principle

6. Classes should only have one reason for change

7. Border Patrol patrol_border accept_illegal_shipments_of_muppets

8. DAMN POSTAL STRIKE! Border guards can't patrol whilst waiting for packages

9. 2. Open/Closed Principle

10. Classes Should be Open for Extension but Closed for Modification

11. Border Guard accept_tequila_bribe

12. Border Guard accept_bribe(bribe)

13. Look for the Abstractions!

14. Liskov Substitution Principle

15. Subtype should be completely substitutable for the Supertype

16. Border Guard drink(Fluid)

17. !=

18. Although Freddy Will be Happy the Guards' Boss won't be!

19. Interface Segregation Principle

20. Clients should not be forced to depend on methods they do not use.

21. Shipment Illegal Muppets circulate_air(airholes_count) ship

22. Dependency Inversion Principle

23. High Level Business Logic shouldn't depend on lower level details.

24. -find muppets -pack muppets -bribe border patrol -phone pedro to come and pick up muppets. -celebrate Freddy's Business Logic : What's the problem here?