Lab #12. Object-oriented programming

Lab #12.1. Transforming a simple class I

Given program (lab12.1.cpp).

#include <iostream>

using namespace std;

class twointegers

{

public:

int a;

int b;

};

int main()

{

twointegers t;

t.a = 5;

t.b = 7;

cout << t.a+t.b << endl;

return 0;

}

/*

int main()

{

twointegers t (5, 7);

cout << t.sum() << endl;

return 0;

}

*/

It prints the sum of numbers 5 and 7. Transform (complement) the program (class twointegers) according to the following terms:

· fields a and b should be transformed to private,

· the program should run fine, if existing main is replaced by the commented main,

· the functionality should not change.

A correct solution: lab12.1a.cpp.

Lab #12.2. Transforming a simple class II

Given program (lab12.2.cpp).

#include <iostream>

using namespace std;

class threedoubles

{

public:

double x;

double y;

double z;

};

int main()

{

threedoubles t;

t.x = 1.1;

t.y = 2.2;

t.z = 3.3;

cout << t.x+t.y+t.z << endl;

threedoubles *tp = new threedoubles;

tp->x = 0.2;

tp->y = 0.3;

tp->z = 0.4;

cout << tp->x+tp->y+tp->z << endl;

delete tp;

return 0;

}

/*

int main()

{

threedoubles t;

t.set (1.1, 2.2, 3.3);

t.printsum ();

threedoubles *tp = new threedoubles (0.2, 0.3, 0.4);

tp->printsum();

delete tp;

return 0;

}*/

It prints the sum of 1.1, 2.2 and 3.3, as well as the sum of 0.2, 0.3 and 0.4. Transform (complement) the program (class threedoubles) according to the following terms:

· fields x, y, z should be transformed to private,

· the program should run fine, if existing main is replaced by the commented main,

· the functionality should not change.

A correct solution: lab12.2a.cpp.