Input file to multiple arrays in C++

Question

I have two files, and I am supposed to input both of them into arrays. One of them is:

2
3
4
5
7
8

The second one is

2
4
5
6
7
8
2
3
4
5
7
8

(it's much longer, but it doesn't matter). I need to have one array with the first 6 numbers, and then I am supposed to check if first six numbers from the second file are the same as the numbers in the second array, same with the next six numbers and so on (like checking for a lottery winner). I guess that I am supposed to load numbers from one file into multiple arrays, but I have no idea how to do it, and I can't find it anywhere.

The code for the first array that I have so far is:

#include<iostream>
#include<fstream>
using namespace std;
int main(){
int numbers[6];
int count = 0;
ifstream inputFile;
inputFile.open("Numbers.txt");
while (count < 20 && inputFile >> numbers[6]){
    count++;
    inputFile.close();
    for (count=0; count < 20; count++)
    cout << numbers[count];}
    return 0;
    }

Another problem is that instead of displaying the numbers correctly, it displays "-858993460" 6 times - even though my code is basically copied from a book...

What is wrong with my code, and how do I input the second file?

Answer 1

Your main problem is doing stuff inside your loop that should not be there. The loop is supposed to run once for each value it reads in from the file. After it is finished is when you should close the file and print the results.

#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    int numbers[6];
    int count = 0;

    ifstream inputFile;
    inputFile.open("Numbers.txt");

    if(!inputFile.is_open()) // always check for errors
    {
        std::cerr << "ERROR opening input file:" << std::endl;
        return 1; // error
    }

    // make sure count < 6 so you don't overflow your array
    while(count < 6 && inputFile >> numbers[count])
    {
        count++;
        // inputFile.close(); // don't close the file yet!!
        //for(count = 0; count < 20; count++) // don't output yet!!
        //  cout << numbers[count];
    }

    // now close your file and output what you have

    inputFile.close();

    for(count = 0; count < 6 /* not 20!! */; count++) // don't output yet!!
        cout << numbers[count] << '\n';

    return 0;
}

Answer 2

This is an example of reading numbers from your first file. This example can be added to, to read numbers from your second file and compare them with the numbers read from the first file.

Updated:

#include <iostream>
#include <fstream>

using namespace std;

int main() {
    int numbers[6];
    int count = 0;
    ifstream inputFile;

    inputFile.open("Numbers.txt");

    // get each number from the file until the end-of-file bit
    // is retrieved.
    while ((inputFile >> numbers[count]) && (count < 6)){
        // iterate count by one
        count++;
    }

    inputFile.close();

    // run through the array of numbers and ouput each index
    for(int i = 0; i < 6; i++) {
        cout << "numbers["  << i  << "] = " << numbers[i] << "\n";
    }
}

Input: "Numbers.txt"

2
3
4
5
7
8

Output: cout

numbers[0] = 2
numbers[1] = 3
numbers[2] = 4
numbers[3] = 5
numbers[4] = 7
numbers[5] = 8

Update:

Faulty Input:

d
3
4
5
7
8

Output

numbers[0] = 0
numbers[1] = 0
numbers[2] = -1527900896
numbers[3] = 32627
numbers[4] = -1527901752
numbers[5] = 32627