2D array not printing out in grid/not full array?

Question

The issue I'm having is that the 2D array is not printing out everything in the array, and when I run the evolve method, it doesn't print out the 2D array the same as the first time. Wondering what's wrong to make it not print out the entire array, and not print the array the same way when the evolve method runs? Each print out of the array needs to be in a 25x75 grid

Desired initial result:

Actual result:

evolve method result: Project 4:

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Arrays;
import java.util.Scanner;

public class Project4 {

    public static void main(String[] args) throws IOException {
        Scanner input = new Scanner(System.in); // Created a scanner
        System.out.println("Enter the file name you would like to use");
        File file = new File(input.nextLine()); // Takes file name to find file
        Scanner inputFromFile = new Scanner(file);
        FileInputStream fileInput = new FileInputStream(file); // reads file
        int r;
        int y = 0;
        int i = 0;
        while ((r = fileInput.read()) != -1) { // goes through each character in
                                                // file, char by char
            char c = (char) r;
            GameOfLife.grid[i][y] = c;
            y++;
            if (y == 75) {
                y = 0;
                i++;
                if (i == 25) {
                    break;
                }
            }
        }
        // Prints the initial environment
        System.out.println("Initial set: ");
        for (int j = 0; j < GameOfLife.grid.length; j++) {
            System.out.print(GameOfLife.grid[j]);
        }
        boolean operate = true;
        while (operate = true) {
            System.out.println("Do you want to see the next generation? Y/N?");
            String q = input.nextLine();
            if (q.equalsIgnoreCase("y")) {
                GameOfLife.evolve();
                for (int j = 0; j < GameOfLife.grid.length; j++) {
                    System.out.print(GameOfLife.grid[j]);
                    operate = true;
                }
            } else {
                operate = false;
                System.exit(0);
            }
        }
    }
}

GameOfLife:

import java.util.Arrays;

public class GameOfLife {

    static final int m = 25; // number of rows
    static final int n = 75; // number of columns
    static char[][] grid = new char[m][n]; // Creates an empty (no dots or
                                            // X's)grid of rows and columns.

    static int count_neighbors(int i, int j) {
        int nn = 0; // number of neighbors of cell(i,j)

        if (i > 0 && j > 0 && grid[i - 1][j - 1] == 'X') {
            nn++;
        }
        ;
        if (i > 0 && grid[i - 1][j] == 'X') {
            nn++;
        }
        ;
        if (i > 0 && j < 72 && grid[i - 1][j + 1] == 'X') {
            nn++;
        }
        ;
        if (j > 0 && grid[i][j - 1] == 'X') {
            nn++;
        }
        ;
        if (j < 72 && grid[i][j + 1] == 'X') {
            nn++;
        }
        ;
        if (j > 0 && i < 22 && grid[i + 1][j - 1] == 'X') {
            nn++;
        }
        ;
        if (i < 22 && grid[i + 1][j] == 'X') {
            nn++;
        }
        ;
        if (i < 22 && j < 72 && grid[i + 1][j + 1] == 'X') {
            nn++;
        }

        return nn;
    }

    static void evolve() {
        for (int i = 0; i < 23; i++) {
            for (int j = 0; j < 73; j++) {
                int s = count_neighbors(i, j);
                if (s < 2) {
                    grid[i][j] = '.';
                }
                if (s == 2 || s == 3) {
                    grid[i][j] = 'X';
                }
                if (s > 3) {
                    grid[i][j] = '.';
                }
            }

        }

    }

}

Answer 1

Add a System.out.println() after each for-loop to start printing the grid on the next line.

// Print out grid.length characters
for (int j = 0; j < GameOfLife.grid.length; j++) {
    System.out.print(GameOfLife.grid[j]);
}
// Print a new line
System.out.println();

Updated

The problem I failed to notice above is that you are printing an entire row in one line, and the whole grid in one (visible) loop. The following System.out.println() would therefore print a blank line after the entire grid is printed. Please see my solution which extracts out the printing of the game, uses a try-catch for the file reader, and removes the unnecessary operate variable at the bottom since you were just exiting anyway.

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Scanner;

public class Project4 {

    private static void printGame() {
        for (char[] row : GameOfLife.grid) {
            for (char c : row) {
                System.out.print(c);
            }
            System.out.println();
        }
    }

    public static void main(String[] args) throws IOException {
        Scanner input = new Scanner(System.in); // Created a scanner
        System.out.println("Enter the file name you would like to use");
        File file = new File(input.nextLine()); // Takes file name to find file
        BufferedReader br = null;
        String line;
        int i = 0;

        try {
            br = new BufferedReader(new FileReader(file));
            while ((line = br.readLine()) != null) {
                for (int col = 0; col < line.length(); col++) {
                    GameOfLife.grid[i][col] = line.charAt(col);
                }
                i++;
                if (i == 25) {
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                br.close();
            }
        }

        // Prints the initial environment
        System.out.println("Initial set: ");
        printGame();

        while (true) {
            System.out.println("Do you want to see the next generation? Y/N?");
            String q = input.nextLine();
            if (q.equalsIgnoreCase("y")) {
                GameOfLife.evolve();
                printGame();
            } else {
                System.exit(0);
            }
        }
    }
}

Answer 2

I think you should try using println this in both places like this:

System.out.println(GameOfLife.grid[j]);

System.out.print() is not flushed automatically, it's only flushed when a newline is written. This means that rather than writing out everything, it might buffer the IO to keep things more efficient.