Question

I’m currently getting started in C++. For the homework I’m currently doing, I have to define a number of classes in one header file. I’m not sure If I’m doing this right. Here is sample of what I’m trying to do.

//classOne.h
class classOne{
    public:
        classOne();
        ~classOne();
        class classInsideClass{
            public:
                classInsideClass
                void hello();
                void print();
        };

}

(I have skipped some code in this sample, like constructor for classOne)

//classOne.cpp
classOne::classInsideClass::classInsideClass(){}
classOne::classInsideClass::hello(){
    cout << ""Hello <<endl;
}

//main.cpp
classOne callingClass;
callingClass.classInsideClass.hello;

I have defined a class inside classOne’s header file. And I have created the functions for the this classInsideClass, inside the classOne’s cpp. Is this the right way of saying, classInsideClass belongs to classOne, or am I not allowed to do this?

Am I calling the functions of classInsideClass correctly in main.cpp? When I try to run this, I get following error;

error:invalid use of ‘class classOne::classInsideClass

If I don’t try and call a function of classInsideClass in main.cpp, it complies fine.

Thanks in advance.

Answer 1

classInsideClass is a type inside of classOne, not an object. If you want to call classInsideClass::hello(), you need an actual instance of classInsideClass:

classOne::classInsideClass callingClass;
callingClass.hello();