Sams Teach Yourself C++ in 21 Days

Special Classes and Functions 509

22: int main()^15

23: {

24: const int MaxCats = 5; int i;

25: Cat *CatHouse[MaxCats];

26:

27: for (i = 0; i < MaxCats; i++)

28: {

29: CatHouse[i] = new Cat(i);

30: TelepathicFunction();

31: }

32:

33: for ( i = 0; i < MaxCats; i++)

34: {

35: delete CatHouse[i];

36: TelepathicFunction();

37: }

38: return 0;

39: }

40:

41: void TelepathicFunction()

42: {

43: cout << “There are “;

44: cout << Cat::HowManyCats << “ cats alive!” << endl;

45: }

There are 1 cats alive!

There are 2 cats alive!

There are 3 cats alive!

There are 4 cats alive!

There are 5 cats alive!

There are 4 cats alive!

There are 3 cats alive!

There are 2 cats alive!

There are 1 cats alive!

There are 0 cats alive!

Listing 15.2 is very much like Listing 15.1 except for the addition of a new func-

tion,TelepathicFunction(). This function, which is defined on lines 41–45,

does not create a Catobject, nor does it take a Catobject as a parameter, yet it can

access the HowManyCatsmember variable. Again, it is worth reemphasizing that this

member variable is not in any particular object; it is in the class, where it is accessible to

any member function. If public, this variable can be accessed by any function in the pro-

gram, even when that function does not have an instance of a class.

OUTPUT

LISTING15.2 continued

ANALYSIS