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Inheritance Problems

Posted on 2005-04-22
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Last Modified: 2010-04-01
Hey everyone, im having a dabble at inheritance. Ive got my two classes and now i need to test my derived class, but nothing is working even when i use the default constructor for it.

Can someone please help me get an example working to work with PartTimeStud. Thanks

#include <iostream>
using namespace std;

class Date {

public:
     Date(int, int, int);
     void setDate( int d, int m, int y);
     bool isLeapYear();
     void printDate() const;
     void setDay( int d );
     void setMonth( int m );
     void setYear( int y);
     int getDay() const;
     int getMonth() const;
     int getYear() const;
     bool operator== (Date& somedate);
     bool operator> (Date& somedate);
     
private:
     int day;
     int month;
     int year;
     
};

Date::Date(int d, int m, int y)
{
     day = d;
     month = m;
     year = y;
}

void Date::setDate( int d, int m, int y){

     day = d;
     month = m;
     year = y;
     
}

bool Date::isLeapYear()
{
     return ( (year % 4) ? false : true);
}

void Date::printDate() const
{
     cout << day << ", "<<  month << ", " <<year;
     
}

void Date::setDay( int d )
{
     day = d;
}

void Date::setMonth( int m )
{
     month = m;
}

void Date::setYear( int y )
{
     year = y;
}

int Date::getDay() const
{
     return day;
}

int Date::getMonth() const
{
     return month;
}

int Date::getYear() const
{
     return year;
}



bool Date::operator== (Date& somedate)
{
      if (somedate.day == day &&  somedate.month == month && somedate.year == year)
          return true;
      else
          return false;
}

bool Date::operator> (Date& somedate)
{
      if (somedate.day > day &&  somedate.month > month && somedate.year > year)
          return true;
      else
          return false;
}


class Student{
public:
      Student(char * surname, Date dob);
      void printStudent();
      char* getName();
      Date getBirthDate();
      int calculateAge(int currentYear);
protected:
      char sname[10];
      Date birthDate;
};

Student::Student(char * surname, Date dob):birthDate(dob)
{
birthDate.setDay(dob.getDay());
birthDate.setMonth(dob.getMonth());
birthDate.setYear(dob.getYear());

strcpy(sname,surname);

}//End constructor


void Student::printStudent(){

cout << "The student named " << sname << " was born on ";
birthDate.printDate();

}//End printStudent

char * Student::getName(){

return sname;

}//End getName

Date Student::getBirthDate(){

return birthDate;

}//End getBirthDate


int Student::calculateAge(int currentYear){

return currentYear-birthDate.getYear();
}


class PartTimeStud:protected Student{
public:
      PartTimeStud(char * surname, Date dob, float coursefee);
      double getfees();
      void printStudentInfo();
private:
      double fees;
};

void PartTimeStud::printStudentInfo(){
      cout << "The student name: " << sname << " was born on ";
birthDate.printDate();
}

double PartTimeStud::getfees(){
      return fees;
}



int main()
{
      
      return 0;
}

I also need to change the print info statement to print out the fees aswell

Thanks for your Time

David
0
Comment
Question by:David_4321
  • 2
3 Comments
 
LVL 86

Accepted Solution

by:
jkr earned 750 total points
ID: 13844341
Your constructor was missing:

class PartTimeStud:public Student{
public:
    PartTimeStud(char * surname, Date dob, float coursefee) : Student(surname, dob), fees(coursefee) {}
    double getfees();
    void printStudentInfo();
private:
    double fees;
};

void PartTimeStud::printStudentInfo(){
    cout << "The student name: " << sname << " was born on ";
birthDate.printDate();
}

double PartTimeStud::getfees(){
    return fees;
}



int main()
{
Date dob ( 10, 10, 2005);
PartTimeStud pts("test", dob, 9.99);
   
     return 0;
}
0
 

Author Comment

by:David_4321
ID: 13844530
Thanks for the reply

I can get that to compile and run however i cannot seem to get any functions working like        getfees, getname etc
0
 
LVL 86

Expert Comment

by:jkr
ID: 13844579
That might be because they're not being called:

int main()
{
Date dob ( 10, 10, 2005);
PartTimeStud pts("test", dob, 9.99);
cout << pts.getfees() << endl;
   
     return 0;
}

outputs '9.99'
0

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