c++ expected unqualified-id (class inheritance) - c++

Question

I have an application that has subclasses of User.
At the moment, I'm trying to pass an int which will be used to identify the user login number, however, I'm having problems declaring my subclass constructor.
User.h
class User
{
public:
User(int);
private:
int loginNumber;
};
User.cpp
User::User(int theLoginNUmber)
:LoginNumber(theLoginNumber) { }
AdminUser.h
class AdminUser : public User
public:
AdminUser(int);
private:
int loginNumber;
};
AdminUser.cpp
AdminUser::User(int theLoginNumber) // requires unqualified-id
:loginNumber(theLoginNumber) {}

Answer 1

You got definition of Admin user constructor wrong, here is the correct one:
AdminUser::AdminUser(int theLoginNumber)
: User(theLoginNumber) { }
Since User doesn't have default constructor, you have to call the parametric one from initialization section.
However loginNumber can be protected in User class:
class User {
public:
User(int);
protected:
int loginNumber;
};
Now you inherit loginNumber as protected so you don't need it in AdminUser:
class AdminUser : public User
public:
AdminUser(int);
};
Note: it contains loginNumber with correct value(set by constructor).
As #Mossi92 noted, you can go a bit further and implement a getter into User class, which will be inherited too:
class User {
public:
User(int);
protected:
int loginNumber;
int login() const noexcept {
return loginNumber;
}
};
However in this case you should think which class access modifier is the best this function. I'd say login number should be something invisible to outer world so I chose protected. This function now can be called only from inherited or friend classes.
Lets add simple print which calls inherited function in constructor:
AdminUser::AdminUser(int theLoginNumber)
: User(theLoginNumber) {
std::cout << login() << "\n";
}
And if we run:
int main() {
AdminUser admin(1234);
return 0;
}
output:
1234