Sams Teach Yourself C++ in 21 Days

Special Classes and Functions 515

7: void Swap (int&, int &);^15

8: void GetVals(int&, int&);

9: void PrintVals(int, int);

10:

11: int main()

12: {

13: void (* pFunc) (int &, int &);

14: bool fQuit = false;

15:

16: int valOne=1, valTwo=2;

17: int choice;

18: while (fQuit == false)

19: {

20: cout <<

➥”(0)Quit (1)Change Values (2)Square (3)Cube (4)Swap: “;

21: cin >> choice;

22: switch (choice)

23: {

24: case 1: pFunc = GetVals; break;

25: case 2: pFunc = Square; break;

26: case 3: pFunc = Cube; break;

27: case 4: pFunc = Swap; break;

28: default: fQuit = true; break;

29: }

30:

31: if (fQuit == false)

32: {

33: PrintVals(valOne, valTwo);

34: pFunc(valOne, valTwo);

35: PrintVals(valOne, valTwo);

36: }

37: }

38: return 0;

39: }

40:

41: void PrintVals(int x, int y)

42: {

43: cout << “x: “ << x << “ y: “ << y << endl;

44: }

45:

46: void Square (int & rX, int & rY)

47: {

48: rX *= rX;

49: rY *= rY;

50: }

51:

52: void Cube (int & rX, int & rY)

53: {

54: int tmp;

LISTING15.5 continued