Programming and Graphics

160 Introduction to C++ Programming and Graphics

public:

fruit();

fruit(q, w, ..., e);

~fruit();

string readcolor(a, b, ..., c) const;

void change(g, o, ..., x);

private:

string color;

string shape;

float size;

};

If we want to make the color of a fruit available to the main program and any
other function that uses objects of the fruit class, we must move the declaration:

string color;

to the public section of the class definition.

Suppose, for example, that a functionoutsidethe fruit class declares

kiwi = fruit();

Ifcoloris a private field, the statement:

cout << kiwi.color;

is unacceptable. However, ifcoloris a public field, this statement is perfectly
acceptable. Class member fields are routinely kept private to prevent inadver-
tent evaluation in unsuspected parts of a code.

Before proceeding to discuss specific class implementations, we emphasize
two important properties regarding variable availability:

• The arguments of the constructor that defines an object, whether public
  or private, are implicitly available to the member functions. Thus, the
  calling arguments of a member function operating on an object include
  by default the arguments of the constructor that defines the object.

For example, suppose that thevendormember function has been defined

as:

void fruit::vendor()

{

...

}