Chapter:9 Inheritance, solved Exercise question book by Robert Lafore

 

OOP BY ROBERT LOFORE

4th Edition

Chapter:9

Inheritance

Question no 5 :

 Derive a class called employee2 from the employee class in the EMPLOY program in this chapter. This new class should add a type double data item called compensation, and also an enum type called period to indicate whether the employee is paid hourly, weekly, or monthly. For simplicity you can change the manager, scientist, and laborer classes so they are derived from employee2 instead of employee. However, note that in many circumstances it might be more in the spirit of OOP to create a separate base class called compensation and three new classes manager2, scientist2, and laborer2, and use multiple inheritance to derive these three classes from the original manager, scientist, and laborer classes and from compensation. This way none of the original classes needs to be modified.

Program source code:

#include <iostream>

#include <conio.h>

using namespace std;

const int LEN = 80; //maximum length of names

////////////////////////////////////////////////////////////////

class employee //employee class

{

private:

 char name[LEN]; //employee name

 unsigned long number; //employee number

public:

 void getdata()

 {

  cout << "\n Enter last name : "; cin >> name;

  cout << " Enter number :"; cin >> number;

 }

 void putdata() const

 {

  cout << "\n Name : " << name;

  cout << "\n Number : " << number;

 }

};

////////////////////////////////////////////////////////////////

class employee2 :public employee

{

private:

 double compen;

 enum paytype{ hourly, weakly, monthly };

 paytype period;

public:

 void getdata(void)

 {

  char a;

  employee::getdata();

  cout << "Enter compensation: ";

  cin >> compen;

  cout << "Enter payment period (h,w,m): ";

  cin >> a;

  switch (a)

  {

  case 'h':

  period = hourly;

  break;

  case 'w':

  period = weakly;

  break;

  case 'm':

  period = monthly;

  break;

  }

 }

 void putdata(void) const

 {

  employee::putdata();

  cout << "Employee compensation: " << compen << endl;

  switch (period)

  {

  case hourly:

  cout << "hourly" << endl;

  break;

  case weakly:

  cout << "weakly" << endl;

  break;

  case monthly:

  cout << "monthly" << endl;

  break;

  }

 }

};

////////////////////////////////////////////////////////////////

class manager : public employee2 //management class

{

private:

 char title[LEN]; //"vice-president" etc.

 double dues; //golf club dues

public:

 void getdata()

 {

  employee2::getdata();

  cout << " Enter title : "; cin >> title;

  cout << " Enter golf club dues : "; cin >> dues;

 }

 void putdata() const

 {

  employee2::putdata();

  cout << "\n Title : " << title;

  cout << "\n Golf club dues : " << dues;

 }

};

////////////////////////////////////////////////////////////////

class scientist : public employee2 //scientist class

{

private:

 int pubs; //number of publications

public:

 void getdata()

 {

  employee2::getdata();

  cout << " Enter number of pubs : "; cin >> pubs;

 }

 void putdata() const

 {

  employee2::putdata();

  cout << "\n Number of publications : " << pubs;

 }

};

////////////////////////////////////////////////////////////////

class laborer : public employee2 //laborer class

{};

////////////////////////////////////////////////////////////////

int main(void)

{

 manager m1, m2;

 scientist s1;

 laborer l1;

 cout << endl; //get data for several employees

 cout << "\nEnter data for manager 1";

 m1.getdata();

 cout << "\nEnter data for manager 2";

 m2.getdata();

 cout << "\nEnter data for scientist 1";

 s1.getdata();

 cout << "\nEnter data for laborer 1";

 l1.getdata();

 //display data for several employees

 cout << "\nData on manager 1";

 m1.putdata();

 cout << "\nData on manager 2";

 m2.putdata();

 cout << "\nData on scientist 1";

 s1.putdata();

 cout << "\nData on laborer 1";

 l1.putdata();

 cout << endl;

 _getch();

}

Program output in Dev c++ :