while loop trouble with array in java

Question

Play method. this method should allow me to enter commands to rotate a certain row or column of a 4x4 array. it needs to be in a loop (i assume while) to always ask for a command, do the rotation, and print it and end when back to the original, I'm having trouble with what i should have as the while loop, i have a default and a current variable, i use puzzle both times so default gets overwritten (this is what is wrong) so the loop doesn't run, i don't really know how to get around this, i know it doesn't need to be puzzle both times however I've kept it in just to show.

import java.util.Scanner;

public class puzzle {

public static final int N = 4;
public static final int NUMBER_OF_ROTATIONS = 5;

public static void main(String[] args) {
    int[][] puzzle = new int[N][N];
    reset(puzzle);
    test(puzzle);
    reset(puzzle);
    scramble(puzzle);
    System.out.println("### Testing puzzle game play\n");
    play(puzzle);
}

public static void print(int[][] puzzle) {
    for (int[] row : puzzle) {
        for (int elem : row) {
            System.out.printf("%4d", elem);
        }
        System.out.println();
    }
    System.out.println();
}

public static void test(int[][] puzzle) {
    System.out.println("### Testing reset method\n");
    print(puzzle);
    System.out.println("### Testing rotate methods\n");
    print(puzzle);
    for (int i = 0; i < N; i++) {
        System.out.println("### rotateColumn(" + i + ")\n");
        rotateColumn(puzzle, i);
        print(puzzle);
        System.out.println("### rotateRow(" + i + ")\n");
        rotateRow(puzzle, i);
        print(puzzle);
    }
    reset(puzzle);
    System.out.println("### Testing random rotations\n");
    print(puzzle);
    for (int i = 0; i < 5; i++) {
        randomRotation(puzzle);
        print(puzzle);
    }
}

public static int[][] reset(int[][] puzzle) {
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++)
            puzzle[i][j] = i * N + j;
    }
    return puzzle;
}

public static void scramble(int[][] puzzle) {
    for (int i = 0; i < NUMBER_OF_ROTATIONS; i++) {
        randomRotation(puzzle);
    }
}


// TODO: Implement method as specified in assignment brief

public static void rotateRow(int[][] arr, int row) {

    int newRow = arr[row][arr.length - 1];
    int nextRow;
    for (int IndexNo = 0; IndexNo < arr.length; IndexNo++) {
        nextRow = arr[row][IndexNo];
        arr[row][IndexNo] = newRow;
        newRow = nextRow;
    }

}


// TODO: Implement method as specified in assignment brief

public static void rotateColumn(int[][] arr, int column) {
    int newCol = arr[arr.length - 1][column];
    int nextCol;
    for (int IndexNo = 0; IndexNo < arr.length; IndexNo++) {
        nextCol = arr[IndexNo][column];
        arr[IndexNo][column] = newCol;
        newCol = nextCol;
    }
}


// TODO: Implement method as specified in assignment brief

public static void randomRotation(int[][] puzzle) {

    int rowrandom = (int) (Math.random() * 3 + 1);
    int colrandom = (int) (Math.random() * 3 + 1);
    int option = (int) (Math.random() * 2 + 1);

    if (option == 1) {
        rotateRow(puzzle, rowrandom);
    } else {
        rotateColumn(puzzle, colrandom);
    }

}

// TODO: Implement method as specified in assignment brief

static void play(int[][] puzzle) {
    reset(puzzle);
    int[][] Default = puzzle;
    print(puzzle);

    for (int i = 0; i < 5; i++) {
        randomRotation(puzzle);

    }
    int[][] Current = puzzle;
    print(puzzle);


    while (Current!=Default) {
        System.out.println("enter row x or col x: ");
        Scanner input = new Scanner(System.in);
        String x = input.nextLine();

        if (x.equals("row 0")) {
            rotateRow(puzzle, 0);
            print(puzzle);

        }
        if (x.equals("row 1")) {
            rotateRow(puzzle, 1);
            print(puzzle);

        }
        if (x.equals("row 2")) {
            rotateRow(puzzle, 2);
            print(puzzle);

        }
        if (x.equals("row 3")) {
            rotateRow(puzzle, 3);
            print(puzzle);

        }
        if (x.equals("col 0")) {
            rotateColumn(puzzle, 0);
            print(puzzle);

        }
        if (x.equals("col 1")) {
            rotateColumn(puzzle, 1);
            print(puzzle);

        }
        if (x.equals("col 2")) {
            rotateColumn(puzzle, 2);
            print(puzzle);

        }
        if (x.equals("col 3")) {
            rotateColumn(puzzle, 3);
            print(puzzle);
        }


    }
}

}

Answer 1

You're not changing the content of int[][] puzzle, you're just setting it to the same array you've passed to the method initially.

If

static void play(int[][] puzzle) {
    reset(puzzle);
    int[][] Default = puzzle;
    print(puzzle);

    for (int i = 0; i < 5; i++) {
        randomRotation(puzzle);

    }

    int[][] Current = puzzle;
    print(puzzle);

should change the values of puzzle, you should have the method return a new array and save that as the current inside your for loop of the play method.

newPuzzle = randomRotation(puzzle);

Like above.