C++ Neural Networks and Fuzzy Logic: Preface

C++ Neural Networks and Fuzzy Logic

by Valluru B. Rao

MTBooks, IDG Books Worldwide, Inc.

ISBN: 1558515526   Pub Date: 06/01/95

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Inheritance

The primary distinction for C++ from C is that C++ has classes. Objects are defined in classes. Classes

themselves can be data items in other classes, in which case one class would be an element of another class.

Of course, then one class is a member, which brings with it its own data and functions, in the second class.

This type of relationship is referred to as a “has−a” relationship: Object A has an Object B inside it.

A relationship between classes can be established not only by making one class a member of another but also

by the process of deriving one class from another. One class can be derived from another class, which

becomes its base class. Then a hierarchy of classes is established, and a sort of parent–child relationship

between classes is established. The derived class inherits, from the base class, some of the data members and

functions. This type of relationship is referred to as an “is−a” relationship. You could have class Rectangle be

derived from class Shape, since Rectangle is a Shape. Naturally, if a class A is derived from a class B, and if

B itself is derived from a class C, then A inherits from both B and C. A class can be derived from more than

one class. This is how multiple inheritance occurs. Inheritance is a powerful mechanism for creating base

functionality that is passed onto next generations for further enhancement or modification.

Derived Classes

When one class has some members declared in it as protected, then such members would be hidden from

other classes, but not from the derived classes. In other words, deriving one class from another is a way of

accessing the protected members of the parent class by the derived class. We then say that the derived class is

inheriting from the parent class those members in the parent class that are declared as protected or public.

In declaring a derived class from another class, access or visibility specification can be made, meaning that

such derivation can be public or the default case, private. Table 2.1 shows the consequences of such

specification when deriving one class from another.