Object Oriented Programming

Given at JCrete 07 at the University of Crete.

Video of the talk available in Greek on Vimeo https://vimeo.com/10550416

Transcript

1. O-oP Object Oriented Programming
2. Knowing Abstract Class Interface Encapsulation Polymorphism • • • • Object Class Class relationships Object relationships • • • •
3. Name Properties Methods State • • • • Object
4. name = Markos age = 27 talk listen me ? ? time Objects
5. Class Name Defines properties Defines methods Defines state (indirectly) • • • •
6. Classes Person name age talk listen Time seconds pass
7. Class Relationships
8. Inheritance [is] Person Student
9. Inheritance [is] Person name age talk listen Student:Person talk listen learn name age registration number
10. Association [uses] Person Mobile
11. Person Mobile dial call Association [uses]
12. dial call Association [uses] ...................................................
13. Aggregation [has] Car Wheel
14. Car wheel Wheel turn type Aggregation [has] steer
15. Cardinality (Multiplicity)
16. car one-to-one wheel
17. car one-to-many bleft bright fleft fright a car has many doors
18. me many-to-many [is another Person borrowing your Cloth(es?)] her him shirt jean hat
19. Primitive Types String int float boolean char null 0 0.0 false '\u0000'
20. Method return name arguments
21. Method Call dial int number
22. Abstract Class [Why you can’t draw a MusicInstrument] Defines properties Defines some methods Defines algorithms • • •
23. Abstract Class [Why you can’t draw a MusicInstrument] Can’t create an Object!
24. Interface [How to .talk() to a Chinese] Specifies behaviour
25. Communication:Interface talk listen gesture Chinese: Communication talk listen gesture Interface [How to .talk() to a Chinese]
26. Polymorphism greek chinese british italian talk talk talk talk
27. Interface vs Abstract Class Purpose Behaviour vs Functionality Implementation None vs Some Inheritance Multiple vs Single • • • • • •
28. Mobile dial Encapsulation
29. Tips
30. Vector persons = new Vector(); if(persons.size() == 0) return true; else return false; Returning boolean
31. Vector persons = new Vector(); return (persons.size() == 0); Returning boolean
32. Vector persons = new Vector() for(int i = 0; i < persons.size(); i++) persons.get(i); Abstraction vs Implementation
33. List persons = new Vector() Iterator iPersons = persons.iterator(); while(iPersons.hasNext()) i.next(); Abstraction vs Implementation
34. Identifying Polymorphism if(calculation.equals(“sum”)) return (x + y); else if(calculation.equals(“sub”)) return (x - y); else if(calculation.equals(“mul”)) return (x * y); else return (x / y);
35. Identifying Polymorphism return calculation.make();
36. Identifying Polymorphism Calculation:Interface make
37. Identifying Polymorphism Add:Calculation make Mul:Calculation make Sub:Calculation make Div:Calculation make
38. Identifying Polymorphism Add:Calculation return (x + y); Mul:Calculation return (x * y); Sub:Calculation return (x - y); Div:Calculation return (x / y);
39. O-oP Object Oriented Programming
40. O-o P