Teach Yourself Borland C++ in 14 Days - portal

106 Day 4
SYNTAX
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code. To remove clutter from the constructor, a class might have an Init() function that is
called from the constructor to perform those startup tasks. This function would never be
called directly by a user of the class. In fact, more than likely bad things would happen if this
function were to be called by a user at the wrong time, so the function is private in order to
protect both the integrity of the class and the user.
Protected member functions are functions that cannot be accessed by the outside world but can
be accessed by classes that are derived from this class. I haven’t talked yet about classes being
derived from other classes, so I’ll save this discussion for a little later when it will make more
sense. I discuss deriving classes in the section “Inheritance.”
The inline function, Form 1:
ClassName {
public:
ReturnType FunctionName();
};
inline ReturnType ClassName::FunctionName() {
statements
}
The function FunctionName is declared within the body of the class ClassName. The function
definition (the function itself) is defined outside the class declaration using the inline
keyword. FunctionName must be proceeded by ClassName and the scope resolution operator.
The inline function, Form 2:
ClassName {
public:
ReturnType FunctionName()
{
statements
}
};
The function FunctionName is declared and defined entirely within the ClassName declaration.
The function is an inline function by virtue of the fact that it is contained within the
ClassName declaration. The inline keyword is not required.
As with data members, member functions can be declared with the static modifier. A static
member function operates more like a regular function than a member function. Specifically,
a static member function cannot access data members of the class. (I’ll tell you why this
restriction exists in just a bit.) Most of the time you will not use static member functions, but
sometimes you will be required to. For instance, some Windows API functions use callbacks
to perform repeated tasks. If you used this kind of function in your class, the callback function
would have to be declared as static.