Thread: Inheritance Problem

In the periodical derived class, i want to be able to output title and publisher on the base class publication where i output the description, how can i do that?

Code:

#include <iostream.h>
#include <string.h>

class publication {
   char title[60];
   char publisher[40];
  public:
   publication(char* t, char* p) {strcpy(title, t); strcpy(publisher,p);}
   virtual void out(ostream &os) const { os << "Publication: " << title << "\n" << "Published by " << publisher << endl; }
};

ostream &operator<<(ostream &os, const publication &x) {
   x.out(os);
   return os;
}

class periodical : public publication {
   char description[20];
  public:
   periodical(char* t, char* p, char* d) : publication(t,p) {strcpy(description, d);} 
   void out(ostream &os) const { os << "Published " << description << endl;}     
};

int main() {
   publication *p[3];
   p[0] = new publication("OOP244 Notes", "Seneca College");
   p[1] = new periodical("Toronto Sun", "Southam News", "Daily");
   /*p[2] = new book("21 Days to a Better You", "Prentice Hall",
		   "Joseph Noodlemeyer", "1-234-5546-3");*/
   for (int i=0; i < 3; i++) {
      cout << *p[i] << '\n';
      delete p[i];
   }
   return 0;
}

i actually put protected:

Code:

class publication {
  protected:
   char title[60];
   char publisher[40];
  public:
   publication(char* t, char* p) {strcpy(title, t); strcpy(publisher,p);}
   virtual void out(ostream &os) const { os << "Publication: " << title << "\n" << "Published by " << publisher << endl; }
};

and was wondering is that is bad or its ok to make them protected? becuase it works if they are

1. There is no valid reason to use iostream.h instead of iostream. (No, being able to omit the line "using namespace std;" or not having to qualify ostream as std::ostream are not valid reasons.)
2. Similarly, there is no valid reason that I can see for using char arrays instead of std::strings.
3. Given all that, the answer to your question is that you need to call publication::out inside your periodical::out function.