Confusion with homework .. infile

[jjh]

So with infile I have this so far:

#define MAXBOOKS 9
ifstream infile("library.txt");
struct Book
{
title[MAXBOOKS]
}
while(true)
{
for(int i = 0; i < MAXBOOKS; i++)
{
char tempTitle[MAXBOOKS];
infile.getline(book.title, MAXLENGTH);
}
}

I also have the main function, but my question is with the getline. My problem is how do i get the book.title to go into the title[0].
if i try to declare it by setting book.title[0] = book.title, I come up with an error obviously.. but how do i get the infile into book.title[0]????

[gasfusion]

struct Book
{
    Title[MAXBOOKS];
};
 
int main() 
{
    Book myBooks;
    int i = 0;
 
    ifstream infile("library.txt");
 
    for (i=0;i<MAXBOOKS; i++)
        infile.getline(myBooks.Title[i], MAXLENGTH);
    return 0;
}
 

[jjh]

Will that work if i am bringing in a a name of a book ex. "Principles of Chemistry", or will i have to use a 2d array ????

[jjh]

this is a test

[gasfusion]

you don't have to use 2D arrays.
You can pass a number to that array and it'll give you the book title back.
What i don't understand is why you're using structs at all.
Unless of course you're planning to save more stuff in that struct.

[jjh]

string tempTitle;
infile.getline(tempTitle,MAXLENGTH);
If I put the infile in for a string and then assigning it into a char array it doesn't work.

I get this error

c:\documents and settings\owner\my documents\visual studio 2005\projects\hw 4\hw 4.cpp(34) : error C2664: 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::getline(_El em *,std::streamsize)' : cannot convert parameter 1 from 'std::string' to 'char *'
with
[
_Elem=char,
_Traits=std::char_traits<char>
]

CAN YOU THINK OF SOMETHING

this is what I have so far.

#include <iostream>
#include <fstream>
#include <string>
using namespace std;
using std::cin;
using std::cout;
using std::endl;
using std::string;
using std::ifstream;
#define MAXBOOKS 9
#define MAXKEYWORDS 3
#define MAXLENGTH 50
struct Book
{
char title[MAXBOOKS];
char keyWord[MAXKEYWORDS][MAXLENGTH];
char position;
};
int fillArray()
{
char title;
char keyword1;
char keyword2;
char keyword3;
Book theBook;
ifstream infile("library.txt");
while(true)
{
for(int i = 0; i < MAXBOOKS; i++)
{
// infile >> theBook.title[i];

string tempTitle;
infile.getline(tempTitle,MAXLENGTH);
//strcpy(theBook.title[i], tempTitle);
cout << theBook.title[i];

for(int j = 0; j < MAXKEYWORDS; j++)
{

}
}
}
return 0;
}

plus a main function

[Banfa]

This

struct Book
{
    Title[MAXBOOKS];
};
 

is not a proper definition because Title has no type. It probably ought to be something like

#define MAXBOOKS              500  // Set these values yourself
#define MAXTITLE                   50
 
struct Book
{
    char Title[MAXTITLE];
};
 

in which case main should be

int main() 
{
    Book myBooks[MAXBOOKS];
    int i = 0;
 
    ifstream infile("library.txt");
 
    for (i=0;i<MAXBOOKS; i++)
        infile.getline(myBooks[i].Title, MAXTITLE);
    return 0;
}
 

[jjh]

#include <iostream>
#include <fstream>
#include <string>
using namespace std;
using std::cin;
using std::cout;
using std::endl;
using std::string;
using std::ifstream;
#define MAXBOOKS 9
#define MAXKEYWORDS 3
#define MAXLENGTH 50
struct Book
{
char title[MAXBOOKS];
char keyWord[MAXKEYWORDS][MAXLENGTH];
char position;
};
int fillArray()
{
char title;
char keyword1;
char keyword2;
char keyword3;
Book theBook;
ifstream infile("library.txt");
while(true)
{
for(int i = 0; i < MAXBOOKS; i++)
{
// infile >> theBook.title[i];

string tempTitle;
infile.getline(tempTitle,MAXLENGTH);
//strcpy(theBook.title[i], tempTitle);
cout << theBook.title[i];

for(int j = 0; j < MAXKEYWORDS; j++)
{

}
}
}
return 0;
}

This is what I have but it doesn't work can you inform me there is something wrong with me infile but I dont know what.

[Banfa]

This is the error

string tempTitle;
infile.getline(tempTitle,MAXLENGTH);
 

getline does not work on type string, it works on array of char.

If you are going to have more than 1 book you need an array of Book structures (or a linked list but let's not complicate things) and finally you have declared you book local to FillArray so as soon as you exit the data will be gone

Book Books[MAXBOOKS];
 
int fillArray()
{
    ifstream infile("library.txt");
 
    for(int i = 0; i < MAXBOOKS; i++)
    {
        infile.getline(Books[i].title, sizeof Books[i].title);
        cout << Books[i].title;
 
        for(int j = 0; j < MAXKEYWORDS; j++)
        {
            infile.getline(Books[i].keyWord[j], sizeof Books[i].keyWord[j]);
        }
    }
 
    return 0;
}
 

[gasfusion]

duh, you're incrementing the struct array, not the .title lol. I'm such an idiot.

[jjh]

I tried this :

for(int i = 0; i < MAXBOOKS; i++)
        {
 
            string tempTitle;
            infile.getline(theBook[i].title ,MAXLENGTH);
            cout << theBook[i].title;
                 }
 

and then i got the error

c:\documents and settings\owner\my documents\visual studio 2005\projects\hw 4\hw 4.cpp(33) : error C2664: 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::getline(_El em *,std::streamsize)' : cannot convert parameter 1 from 'char' to 'char *'
with
[
_Elem=char,
_Traits=std::char_traits<char>
]

The message i am trying to bring it is "Principles of chem"

[Banfa]

Not if you are using the structure

struct Book
{
  char title[MAXTITLE];
  char keyWord[MAXKEYWORDS][MAXLENGTH];
  char position;
};
 
struct Book theBook[MAXBOOKS];
 

you aren't so I suspect you aren't doing that or you haven't change the code correctly.

[jjh]

Ok i got that alright and thank you, but one other thing...
The file I am wanting to bring in, is read like this...

Title
keyword
keyword
$

my problem now is how do I make the key words is a single array... Is there a way to call theBook[i].keyword[j] and have j as a inside for loop???

[Banfa]

See this post

http://www.thescripts.com/forum/post2107947-9.html

that I have already made to this thread.

[jjh]

Oh I am sorry i didn't even see it. Thank you so much.

[jrjan1]

Can I ask a question on this thread?

What if you have no idea how big the infile is? How do you set MAXBOOKS and MAXLENGTH?