1. Introduction to Programming Lecture 40

2. Class Class is a user defined data type.

3. Data Hiding

4. Public Interface

5. Yes you can use user defined data type as a member of the class Class can contain objects.

6. Example class Date { private : int month, day, year ; int month, day, year ; public : // member functions // member functions } ;

7. Example class Person { private : private : char * name ; char * name ; char * address ; char * address ; Date dateOfBirth ; // member object Date dateOfBirth ; // member object public : public : // public member functions... // public member functions... } ;

8. Person :: Person ( char * name, char * address, int day, int month, int year ) { dateOfBirth.setDay ( dy ) ; dateOfBirth.setMonth ( mn ) ; dateOfBirth.setYear ( yr ) ; // statement ( s ) ; }

9. Initializer List

10. Person :: Person ( char * name, char * address, int day, int month, int year ) : Date ( int month, int day, int year )

11. Constructor Date :: Date ( int day, int month, int year ) { cout << “Inside Date constructor ” ; } Person :: Person ( char * name, char * address,int day, int month, int year ) : Date ( month, day, year ) { cout << “Inside Person constructor” ; }

12. Destructor ~ Date ( ) { cout << “Inside Date destructor ” ; } ~ Person ( ) { cout << “Inside Person destructor” ; }

13. Example class Column { private : private : int size ; int size ; public : public : Column ( ) Column ( ) { cout << "Column Created" << endl ; cout << "Column Created" << endl ; } void display ( ) ; void display ( ) ; void set ( int ) ; void set ( int ) ; ~ Column ( ) ~ Column ( ) { cout << "Column destroyed" << endl ; cout << "Column destroyed" << endl ; } } ;

14. Example class Row { private : private : int size ; int size ; Column col ; Column col ; public : public : void set ( int ) ; void set ( int ) ; Row ( ) { cout << "Inside Constructor for object Row" << endl ; cout << "Inside Constructor for object Row" << endl ; } ~ Row ( ) ~ Row ( ) { cout << "Row destroyed" << endl ; cout << "Row destroyed" << endl ; } void display ( ) ; void display ( ) ; } ;

15. Example class Matrix { private : private : Row row ; Row row ; int size ; int size ; public : public : Matrix ( ) Matrix ( ) { { cout << "Matrix Created" << endl << endl ; cout << "Matrix Created" << endl << endl ; } ~ Matrix ( ) ~ Matrix ( ) { cout << "Matrix destroyed" << endl << endl ; cout << "Matrix destroyed" << endl << endl ; } void display ( ) ; void display ( ) ; } ;

16. main( ) { Matrix m ; m.display ( ) ; } Example

17. Column Created Inside Constructor for object Row Matrix Created …. Matrix Destroyed Row Destroyed Column Destroyed Output

18. Code Reuse

19. const Date dateOfBirth ;

20. Structure inside a structure

21. Class inside a class

22. Example class Outer {……. class Inner1 class Inner1{ private : // Data members //data functions public : // Data members //data functions } ; //data members //data functions } ;

23. Class inside a class Outer Inner1 Inner2

24. Friend

25. Example class Outer { public : class Inner ; friend class Inner ; class Inner { friend class outer ; // Data members }; // Member functions } ;

26. ReturnType className :: functionName ( ) { // Statement ( s ) ; definition } }

27. Outer :: Inner :: Inner ( ) { // definition }

28. Example class Outer { class Inner1 { class Inner2 { class Inner3 class Inner3 { // Data members and functions // Data members and functions // and perhaps more inner classes // and perhaps more inner classes } ; } ; // Data members and functions // Data members and functions } ; // Data members and functions } ; 48: