In defining a member function whose declaration is in a class,you use the dot operator to specify that the member function being defined belongs in the class,as
class foo
{
public:
// other members
void output( );
// other members
};
void foo.output( )
{
/* whatever */
}

Question

Quizplus · Accepted Answer

The correct syntax for defining a member function whose declaration is in a class involves using the scope resolution operator (::) instead of the dot operator. The correct syntax for defining the output() member function in the foo class would be:

void foo::output()
{
  /* function body */
}

In Defining a Member Function Whose Declaration Is in a Class,you