Converting istream operator >> to istream getline

Question

I'm attempting to read lines from a file using istream& getline instead of using istream& operator .

result cpp

#include "Result.h"

Result::Result()
{
    Coursename[0] = '\0';
}

Result::Result( const char * nam, unsigned scor )
{
    strncpy( Coursename, nam, CourseNameSiz );

    score = scor;
}
//istream& getline( istream & input, Result & Re, ',' )
istream & operator >>( istream & input, Result & Re )
{
  //getline(Re.Coursename, input, ',');
  input >> Re.Coursename >> Re.score;
  return input;
}

ostream & operator <<( ostream & os, const Result & Re )
{
  os << "  Unit Name:  " << Re.Coursename << '\n'
     << "  Result: " << Re.score << '\n';
  return os;
}

int Result::GetScore() const
{
  return score;
}

inline void Result::SetScore( unsigned scor )
{
  score = scor;
}

result header

#ifndef RESULT_H
#define RESULT_H

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

using namespace std;

const unsigned CourseNameSiz = 10;

class Result
{
    public:

        Result();

        Result( const char * nam, unsigned scor );

        int GetScore() const;
        // Get the number of s.

        void SetScore( unsigned scor );
        // Set the number of score.
        //string Result:GetCourseName() const;

        friend ostream & operator <<( ostream & os, const Result & Re );
        //friend istream & getline( istream & input, Result & Re, ',' );
        friend istream & operator >>( istream & input, Result & Re );

    private:
        char Coursename[CourseNameSiz];
        //string Coursename[CourseNameSiz]; // Unit name, C style string
        int  score; // number of scores
        string str;

}; 
#endif // RESULT_H

This all works exactly how I want it to but I need to change it so instead of reading in a word at a time, I want to use istream& getline with a delimiter. Most of the comments in the code is my attempt on changing to the getline method. I made an array of strings and as a test tried to put the first item in read file into it but obviously didnt work.

Im just looking for a little guidance here. Thanks in advance

EDIT:: Input File: rinput.txt

31525 1 4
JPN_101 3 Japanese, 90,
ICT 4 example1, 91,
TIC 4 example2, 92,
CIT 4 example3, 93

So where it says example1, and 91, those are the two items Im attempting to use getline for with a delimiter because I want to use spaces in my read file

The other information is read in different classes which I will change to getline method when I get this one to work.

Output file: routput.txt

Student ID: 31525
Semester:   1
  Unit:  JPN_101
  Credits: 3
  Unit Name:  Japanese
  Result: 90

  Unit:  ICT
  Credits: 4
  Unit Name:  example1
  Result: 91

  Unit:  TIC
  Credits: 4
  Unit Name:  example2
  Result: 92

  Unit:  CIT
  Credits: 4
  Unit Name:  example3
  Result: 93

Number of courses = 4
Total credits     = 15

This is the output of when im using the operator method with the array chars.

include\Result.h|28|error: expected identifier before ','|

include\Result.h|28|error: expected ',' or '...' before ','|

||=== Build failed: 2 error(s), 0 warning(s) (0 minute(s), 1 second(s)) ===|

which points to the header file line 28 which is friend istream & getline( istream & input, Result & Re, ',' );

I Believe I just dont understand why just changing it to array of strings ( string Coursename[CourseNameSiz]; ) then just changing the operator method to a getline method doesnt just make it return the input like it does for the operator method.

I hope I explained that right, Im having someone translate this a little to help me word it better.

Thankyou

Answer 1

This line

friend istream & getline( istream & input, Result & Re, ',' );

won't compile because you have a constant as the third parameter instead of a parameter declaration.

In your case, because you hard code ',' in the call to getline inside the method, you don't need to pass the comma in at all.

friend istream & getline( istream & input, Result & Re);

Similarly, when you define the function, you don't need the ',' in the function definition:

istream& getline( istream & input, Result & Re)
{
  getline(Re.Coursename, input, ',');
  return input;
}

Note that you still need the comma in the internal call to getline .

This should fix up the compiler errors you have listed, you will still need to debug your code if it doesn't work.