Question

For an ungraded C++ lab, we have practice with structs. I'm having a hard time calling the functions relating to our book struct correctly. The issues lie in main(). Here is the .cpp:

#include "book.h"

void add_author(Book& book){
        if (book.num_auth==3){
            std::cout<<"\nA book can't have more than 3 authors!";
        }
        else{
            std::cout<<"\nAdd Author: ";
            getline(std::cin, book.authors[book.num_auth]);
            book.num_auth++;
        }
};

void remove_last(Book& book){
        if(book.num_auth<=1){
            std::cout<<"\nA book must have at least 1 author!";
        }
        else{
            book.authors[book.num_auth-1]="";
            book.num_auth=book.num_auth-1;
        }
};

std::ostream& print(std::ostream& out, Book book){
        std::cout<<"\n\nTitle: "<<book.title<<"\nAuthors: ";
        for(int i=0; i<book.num_auth; i++){
            std::cout<<"\n\t"<<book.authors[i];
        }
        std::cout<<"\nGenre: "<<book.genre<<"\nPublisher: "<<book.publisher<<std::endl;
        return out;
};

void initializeBook(Book& book){
        std::cout<<"\nEnter the Title of the book: ";
        getline(std::cin, book.title);

        std::cout<<"\nGenre: ";
        getline(std::cin, book.genre);

        std::cout<<"\nPublisher: ";
        getline(std::cin, book.publisher);

        book.authors=new std::string[3];
        std::cout<<"\nFirst Author: ";
        getline(std::cin, book.authors[0]);
        book.num_auth=1;
}

int main(){

Book book;                                                                                                                       //QUESTION//what would this do?
std::string Book = initializeBook(book.title, book.genre, book.publisher, book.authors); //QUESTION//how do I call this function correctly?
add_author(Book& book);                                                                                               //QUESTION//same as above
remove_last(Book& book);                                                                                           //QUESTION//same as above

return 0;
};

and the .h:

#ifndef __BOOK_H_INCLUDED__
#define __BOOK_H_INCLUDED__
#include <iostream>

struct Book{
    std::string title;
    std::string genre;
    std::string publisher;
    int num_auth;
    std::string* authors;

};

void add_author(Book& book);
void remove_last(Book& book);
std::ostream& print(std::ostream& out, Book book);
void initializeBook(Book& book);

#endif

Answer 1

Use this :

int main(){

Book book; //QUESTION//what would this do?

initializeBook(book); //QUESTION//how do I call this function correctly?

print(std::cout, book);

add_author(book); //QUESTION//same as above

remove_last(book); //QUESTION//same as above

return 0;

};

==================================
SEE OUTPUT

Files E saved main.cpp 48 } clang version 7.0.0-3-ubuntu0.18.04.1 > clangh-7 -pthread -o main main.cpp ./main main.cpp 49 50 int main() { book.h Enter the Title of the book; Harry 51 52 Book book; Genre: poter Publisher: ddd 53 //QUESTION//what would this do? initializeBook (book); //QUESTION//how do I call this function correctly? First Author: A print(std::cout, book); add_author(book); 56 Title: Harry Authors: 57 //QUESTION// same as above remove_last (book); Genre: poter Publisher: ddd //QUESTION// same as above Add Author: 0 return 0;

PLEASE COMMENT if there is any concern.

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