Using objects of a class in another class?

Question

I have created a class called Book and it can have many Books. But I want to create a class shelf which can contain only 10 of Books if it is greater than than 10 ten it should print Error Message! But I cannot think of a way to make class shelf. So far I have done this :

#include <iostream>
#include <string>
using namespace std;

class Book{
private:
    string bookName;
    int pNum;

public:
    Book();
    Book(string tempName, int tNum){
        setName(tempName);
        setPageNum(tNum);
    }

    void setName(string bName){
    bookName = bName;
    }



    void setPageNum(int tempNum){
        pNum = tempNum;
    }

    string getName(){
     return bookName;

         }
    int getPageNum(){
        return pNum;

         }
};

class Shelf{
    public:
    Book nBook[10];
    void addbook();
void Book::addbook(Book nBook[10])
{
    for(int i = 0; i<10; i++)
        nBook[i] = nBook[i].setName(string bName)

}


};
int main(){

    Book math = Book("math", 500);
    Book abcd = Book("abcd", 501);


    cout << English.getName() <<" "<<English.getPageNum()<<endl;
    cout << German.getName() <<" "<<German.getPageNum()<<endl;


}

Answer 1

You can use the standard vector class to store the Book objects in the shelf. In the example below, the book object will be copied when added to the Shelf

#include <vector>
using namespace std;
class Shelf{
public:
  vector<Book> books;

  bool addbook(Book book)
  {
    if(books.size() > 10) 
      {
        return false;
      }
    else 
      {
        books.push_back(book);
        return true;
      }
  }
};

Answer 2

There are many ways to implement this. Note the default constructor of class Book. Let me know if you have any questions.

#include <iostream>
#include <string>
using namespace std;

class Book{
private:
    string bookName;
    int pNum;

public:
    Book(){
    }
    Book(string tempName, int tNum){
        setName(tempName);
        setPageNum(tNum);
    }

    void setName(string bName){
    bookName = bName;
    }

    void setPageNum(int tempNum){
        pNum = tempNum;
    }

    string getName(){
     return bookName;

    }
    int getPageNum(){
        return pNum;

    }
};

class Shelf{
    public:
    Book nBook[10];
    int numberOfBooks;
    void addbook(Book);

    Shelf()
    {
       numberOfBooks = 0;
    }

    bool addBook(Book newBook)
    {
        if (numberOfBooks == 10)
        {
            return false;
        }
        else
        {
            nBook[numberOfBooks] = newBook;
            numberOfBooks++;
            return true;
        }
    }


};
int main(){

    Book English = Book("math", 500);
    Book German = Book("abcd", 501);


    Shelf bookShelf = Shelf();

    bookShelf.addBook(English);

}