How to output functions output into file?

Question

I have a project that requires me to output the data from 2 files. Put them into their own arrays. Calculate the data from 1 of the files into a function. Then output the functions into a whole new file. This is what I have so far and right now I'm trying to figure out how to output the function output into a new file. When I try now, I get outputs in the file like "NULL NULL". I also have to align the data in columns.

#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>

using namespace std;

char states();
char stData();

char states()
{
    const int SIZE = 0;
    ifstream myfile("csc114_states.txt");
    string line, myArray[SIZE];
    if (myfile.is_open())
    {
        for (int i = 1; i < SIZE; i++)
        {
            myfile >> myArray[i];
            cout << myArray[i];
            cout << endl;
        }
        myfile.close();
    }
    myfile.open("csc114_states.txt");
    if (myfile.is_open())
    {
        string tp;
        while (getline(myfile, tp))
        {
            cout << tp << "\n";
        }
        myfile.close();
    }
    else
    {
        cout << "Unable to open file." << endl;
        return 0;
    }

    return 0;
}

char stDATA()
{
    const int size1 = 0;
    const int size2 = 0;
    string myArray2[size1][size2], line;
    ifstream myfile2("csc114_data.txt");

    if (myfile2.is_open())
    {
        for (int i = 0; i < size1; i++)
        {
            for (int j = 0; j < size2; j++)
            {
                myfile2 >> myArray2[i][j];
                cout << myArray2[i][j];
                cout << endl;
            }
        }
        myfile2.close();
    }
    myfile2.open("csc114_data.txt");
    if (myfile2.is_open())
    {
        string tp2;
        while (getline(myfile2, tp2))
        {
            cout << setw(0) << tp2 << "\n";
        }
        myfile2.close();
    }
    else
    {
        cout << "Unable to open file." << endl;
        return 0;
    }
    return 0;
}

int main()
{
    ofstream bigFile("csc114_output.txt");
    if (bigFile.is_open())
    {
        bigFile << states() << stDATA();

        bigFile.close();
    }
    else
    {
        cout << "Unable to open files.";
    }

    return 0;
}