help with class structure assignment

I'm doing an assignment where you have to create class structures. The problem I'm having is when you read in a string into the array. Here is my program so far:

Code:

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

const int NUMCONS = 15;
class author_name {
      public:
             string last;
             string first;
};
class other_info {
      public:
             string publisher;
             int year;
};

class book_info {
      public:
             
             string title; 
             int pages;
             string genre;
             other_info other;
};

class mybooks {
      public:
             author_name name;
             book_info book;
};
void readdata (mybooks [], int &);
void prettyprint (mybooks [], int);
int main () 
{
    mybooks library[NUMCONS];
    int num;
    

       readdata (library, num);
       prettyprint (library, num);
    
    
    
    return 0;
}
void readdata (mybooks library [], int &num)
{
     ifstream cfile("program8in.dat");
     cfile >> num;
        
     
     for (int count = 0; count < num; count++) {
         cfile >> library[count].name.last;
         cfile >> library[count].name.first;
         cfile >> library[count].book.title;
         cfile >> library[count].book.pages;
         cfile >> library[count].book.genre;
         cfile >> library[count].book.other.publisher;
         cfile >> library[count].book.other.year;
         
     
     }
     cfile.close();
     return;
}
void prettyprint (mybooks library [], int num)
{    
     ofstream dbfile("program8.out");
     
     for (int count= 0; count < num; count++) {
         dbfile << "\t" << library[count].name.last;
         dbfile << "\t" << library[count].name.first;
         dbfile <<"\t" << library[count].book.title;
         dbfile <<"\t" << library[count].book.pages;
         dbfile <<"\t" << library[count].book.genre;
         dbfile <<"\t" << library[count].book.other.publisher;
         dbfile <<"\t" << library[count].book.other.year;
         dbfile << endl;
     } 
     
     dbfile.close();
     return;
}

Here is my data file:

Code:

2
Jk Rowling
Harry  167 Fantasy Scholastic 1999
JRR Tolkien
LOTR 999 Fantasy Penguin 1956

And this is my output:
Jk

Code:

	Rowling	Harry	167	Fantasy	Scholastic	1999
	JRR	Tolkien	LOTR	999	Fantasy	Penguin	1956

But let's say I want the title to be "Harry Potter". The program will read in "Harry" into a different location in the array from "Potter".

I've tried using getline(), because that's the only thing I can think of to do that.

I tried this:

Code:

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

const int NUMCONS = 15;
class author_name {
      public:
             string last;
             string first;
};
class other_info {
      public:
             string publisher;
             int year;
};

class book_info {
      public:
             
             string title; 
             int pages;
             string genre;
             other_info other;
};

class mybooks {
      public:
             author_name name;
             book_info book;
};
void readdata (mybooks [], int &);
void prettyprint (mybooks [], int);
int main () 
{
    mybooks library[NUMCONS];
    int num;
    

       readdata (library, num);
       prettyprint (library, num);
    
    
    
    return 0;
}
void readdata (mybooks library [], int &num)
{
     ifstream cfile("program8in.dat");
     cfile >> num;
        
     
     for (int count = 0; count < num; count++) {
         cfile >> library[count].name.last;
         cfile >> library[count].name.first;
         getline(cfile, library[count].book.title);
         cfile >> library[count].book.pages;
         getline(cfile, library[count].book.genre);
         getline(cfile, library[count].book.other.publisher);
         cfile >> library[count].book.other.year;
         
     
     }
     cfile.close();
     return;
}
void prettyprint (mybooks library [], int num)
{    
     ofstream dbfile("program8.out");
     
     for (int count= 0; count < num; count++) {
         dbfile << "\t" << library[count].name.last;
         dbfile << "\t" << library[count].name.first;
         dbfile <<"\t" << library[count].book.title;
         dbfile <<"\t" << library[count].book.pages;
         dbfile <<"\t" << library[count].book.genre;
         dbfile <<"\t" << library[count].book.other.publisher;
         dbfile <<"\t" << library[count].book.other.year;
         dbfile << endl;
     } 
     
     dbfile.close();
     return;
}

With this data file:

Code:

2
Jk Rowling
Harry Potter  
167 
Science Fiction/Fantasy 
Scholastic 
1999
JRR Tolkien
Lord of the Rings 
999 
Science Fiction
Penguin Classics 
1956

But it gives me crazy output, like this:

Code:

	Jk	Rowling		211400			211400
				205920			205936

So if someone can explain what I'm doing wrong, I'd be quite grateful.

Take a look at this code:

Code:

     for (int count = 0; count < num; count++) {
         cfile >> library[count].name.last;
         cfile >> library[count].name.first;
         getline(cfile, library[count].book.title);
         cfile >> library[count].book.pages;
         getline(cfile, library[count].book.genre);
         getline(cfile, library[count].book.other.publisher);
         cfile >> library[count].book.other.year;
     }

After you cin>> name.first and name.last, you will have read "Jk" and "Rowling", respectively, but you've left the newline in the stream. The call to getline will receive an empty line, and when you try to convert that empty string to a number, you get something completely random like 211400.

So, you have to get rid of the newline. Perhaps the easiest way to do this would be to use getline() to get the line "Jk Rowlings" into one string, and then use stringstreams to parse the two parts of that line.

Stringstreams are covered in this FAQ. In the FAQ, numbers are being extracted from the string, but it's the same idea for strings. http://faq.cprogramming.com/cgi-bin/...&id=1043284385

Is there another way to get rid of the newline character, like cin.ignore or something like that?

Originally Posted by Crcullen3916

Is there another way to get rid of the newline character, like cin.ignore or something like that?

There's more than one way to do pretty much anything, but I'd recommend learning to use stringstreams. Really, it's not hard, and they are terribly useful things.

You could use ignore() if you wanted to, just like when you stop the console from closing:

Code:

in.ignore ( std::numeric_limits<std::streamsize>::max(), '\n' );

From http://faq.cprogramming.com/cgi-bin/...&id=1043284385

But using stringstreams would be a good idea, in case you want to expand your program in the future or something.