C++ how would you read this file into an array.

Applications Programming
1

here is the pesudo file.

REREREEEEEERRRREER
SOMEStrinG1234 RERRRR  EEERRRREER
SOMEStrinG1224 REREREEEREERRR REE
SOMEStrinG1214 REREREREREREREEEER
SOMEStrinG1204 RERE EEEEEERRRRRRR
SOMEStrinG1294 REREEREEE ERRRREER
SOMEStrinG1284 REREREEEEEERR REER

here is my attempted code

#include <iostream>
#include <fstream>
#include <string>
#include <cmath>

#define SIZE 255
using namespace std;

int main(int argc, const char * argv[])
{


    ifstream inFile;
    inFile.open("inFile", ifstream::in);
    if (!inFile) {
        cerr << "Error: file could not be opened" << endl;
        return -1;
    }

    // reading file line by line // EOF = no chars;
    string line;
    int i = 0;
    while (inFile.good()) {
        getline(inFile, line, '\n');
        cout << line << " line// " << i << endl;
        i++;
    }
    cin.clear();
    
    char studentID;
    string grades;
    for (int i = 1, k = 0; line.length(); i++, k++) {
        cin >> studentID[k] >> grades[k];
    }

    cout << studentID[2] << endl << grades[2][1];
    
    ofstream outFile;
    outFile.open("outData.txt", ifstream::out);
    if (!outFile) {
        cerr << "Error: file could not be opened" << endl;
        return -2;
    }

    return 0;
}

The context is this is for an exercise out book I am attempting to solve.
the point I am at in my coding is i would like to test my results by adding this statement inline.

    cout << studentID[2] << endl << grades[2][1];

But it is not outputting anything to common out.
The section I am working in is about c++ arrays (non vector)
So that is the scope of solution(s) feedback I am looking for

Thanks in advance.

2

Take a close look at this:

cin >> studentID[k]

if studentID is a 2d array of characters, what do you get by specifying both indexes? A single character, which is what you end up reading.

If you want to read a string, try

cin >> studentID[k]

But you're going to run into problems with garbage stuck in your input because cin hits a newline and refuses to read past it. Are you allowed to use C-style fgets/sscanf ?

3

"But you're going to run into problems with garbage stuck in your input because cin hits a newline and refuses to read past it. Are you allowed to use C-style fgets/sscanf ? "

No requirements / limits here other than I learn what I am doing. It is not for a class. Just an exercise out of a book. I would just like to avoid using vectors. As I am still trying to work with basic arrays for now.

4

I keep noticing more problems with your strings... string[SIZE] is an array of 256 strings, not 256 characters!

I would use C I/O, then. It's easier and more efficient, and deals with straightforward arrays.

We use fgets and sscanf, rather than plain scanf, because plain scanf is subject to the same problems -- it'll get stuck on a newline until you flush input or whatever. Read entire lines at a time then process them, and nothing gets stuck.

#include <stdio.h>

// 2D character arrays, each row holds up to 64 characters
char studentID[256][64];
char grades[256][64];

int main(void)
{
        int n=0;
        char firstline[256], buf[256];

        fgets(firstline, 256, stdin); // Read a line of up to 256 characters into firstline

        // read a line into buf, then split it into studentid and grades
        while(fgets(buf, 256, stdin) != NULL)
        {
                // The string "%s %s" means "two strings separated by a space"
                // It expects two pointers afterwards, one for each %s
                // studentID[n] is a pointer to a 1d array inside the 2d one.
                sscanf(buf, "%s %s", studentID[n], grades[n]);
                n++;
        }
}