This lecture describes the basic concepts of OOP such as Abstraction, Inheritance, Composition and aggregation

1. Object Oriented Programming Department of Computer Science, University of Peshawar Lecture 03 Introduction Introduction Lec - 03

13. Lecture 03 Introduction Department of Computer Science, University of Peshawar

14. Declaration of an Object class Rectangle { private: int width; int length; public: void set(int w, int l); int area(); } main() { Rectangle r1; r1.set(5, 8); } r1 is statically allocated width length r1 width = 5 length = 8 Lecture 03 Introduction

19. Example - Inheritance Lecture 03 Introduction Department of Computer Science, University of Peshawar Person Teacher Student Doctor

20. Inheritance Concept Rectangle Triangle Polygon class Polygon { private: int width, length; public: void set(int w, int l); } class Rectangle{ private: int width, length; public: void set(int w, int l); int area(); } class Triangle{ private: int width, length; public: void set(int w, int l); int area(); } Lecture 03 Introduction

21. Inheritance Concept Rectangle Triangle Polygon class Polygon { protected: int width, length; public: void set(int w, int l); } class Rectangle : public Polygon { public: int area(); } class Rectangle{ protected: int width, length; public: void set(int w, int l); int area(); } Lecture 03 Introduction

22. Inheritance Concept Rectangle Triangle Polygon class Polygon { protected: int width, length; public: void set(int w, int l); } class Triangle : public Polygon { public: int area(); } class Triangle{ protected: int width, length; public: void set(int w, int l); int area(); } Lecture 03 Introduction

23. Inheritance Concept Point Circle 3D-Point class Point { protected: int x, y; public: void set(int a, int b); } class Circle : public Point { private: double r; } class 3D-Point: public Point { private: int z; } x y x y r x y z Lecture 03 Introduction

26. Example – “IS A” Relatioship Lecture 03 Introduction Department of Computer Science, University of Peshawar Person Name Age Gender Eat walk Student Program Study_year Study Heldexam Teacher designation salary Teach Take_exam Doctor designation salary Check up prescribe

27. Example – “IS A” Relatioship Lecture 03 Introduction Department of Computer Science, University of Peshawar shape color coordinates Draw rotate Set color Circle radius draw Compute area Line length Draw Triangle angle Draw Compute area

30. Example Reuse Lecture 03 Introduction Department of Computer Science, University of Peshawar Shape color coordinates Draw rotate Set color Circle radius draw Compute area Line length Draw Triangle angle Draw Compute area

31. Example – “IS A” Relatioship Lecture 03 Introduction Department of Computer Science, University of Peshawar Person Name Age Gender Eat walk Student Program Study_year Study Heldexam Teacher designation salary Teach Take_exam Doctor designation salary Check up prescribe

32. Example – “IS A” Relatioship Lecture 03 Introduction Department of Computer Science, University of Peshawar Person Name Age Gender Eat walk Student Program Study_year Study Heldexam Teacher designation salary Teach Take_exam Doctor designation salary Check up prescribe

33. Example Reuse Lecture 03 Introduction Department of Computer Science, University of Peshawar Person Name Age Gender Eat walk Student Program Study_year Study Heldexam Teacher designation salary Teach Take_exam Doctor designation salary Check up prescribe

36. Example Generalization Lecture 03 Introduction Department of Computer Science, University of Peshawar Student Name Age gender Program Study_year Eat walk Study Heldexam Teacher Name age gender designation salary Eat walk Teach Take_exam Doctor Name Age gender designation salary Eat walk Check up prescribe

37. Example - Generalization Lecture 03 Introduction Department of Computer Science, University of Peshawar Person Name Age Gender Eat walk Student Program Study_year Study Heldexam Teacher designation salary Teach Take_exam Doctor designation salary Check up prescribe

39. Example – Sub-typing (Extension) Lecture 03 Introduction Department of Computer Science, University of Peshawar Person Name Age Gender Eat walk Student Program Study_year Study Heldexam

41. Example – Specialization (Restriction) Lecture 03 Introduction Department of Computer Science, University of Peshawar Person Age: [0…..100] Set Age(a) Adult Age: [18….100] Set Age(a) Age = a If age<18 Error Else Age = a

42. Example – Specialization (Restriction) Lecture 03 Introduction Department of Computer Science, University of Peshawar integerSet ---------- Add ( element) Natural Set ------- Add ( element) Add element To the set If element<1 Error Else Add element to the set

45. Example – Specific Behavior Lecture 03 Introduction Department of Computer Science, University of Peshawar shape color coordinates Draw rotate Set color Circle radius draw Compute area Line length Draw Triangle angle Draw Compute area

52. Types of Inheritance

54. Example – Multiple Inheritance

55. Example – Multiple Inheritance Land Vehicle Vehicle Water Vehicle Car Amphibious Vehicle Boot

58. ..Problems with multiple Inheritance..