Java : GameOfLife : How could I count all the alive cells around?

Question

I am trying to create a gameoflife in java for a homework.

First of all, i have to create an array from an interface class.

Then, i fill this array with alive cells and empty cells such as :

public World(int n, int p) {

    numberOfRow = n;
    numberOfCol = p;

    myWorld = new Cell[numberOfRow][numberOfCol];
    AliveCell cellNew = new AliveCell(1, "X");
    DeadCell cellDead = new DeadCell(0,"O");
    EmptyCell emptyCell = new EmptyCell("");
    int gameTurn = 0;
    int countAgeCell = 0;
    boolean isOccupied = false;
    Random numberRand = new Random();
    Random numberXRand = new Random();
    Random numberYRand = new Random();
    numberRandomCellAlive = numberRand.nextInt((2500 - 1 + 1) +1);
    compteurCellAliveGenerated = 0;

for(int i = 0; i < this.myWorld.length; i++) {
        for(int j = 0; j < this.myWorld.length; j ++) {
            myWorld[i][j] = emptyCell;
        }
    }

for(int i =0; i < this.myWorld.length -1; i ++) {
        for(int j = 0; j < this.myWorld.length -1; j++) {
            if(compteurCellAliveGenerated < numberRandomCellAlive) {

            int posXRandomCellAlive = numberXRand.nextInt((50 - 1));
            int posYRandomCellAlive = numberYRand.nextInt((50 - 1));

            myWorld[posXRandomCellAlive][posYRandomCellAlive] = cellNew;

            isOccupied = true;
            compteurCellAliveGenerated++;
        }

Here, i can print my array and it all works. I mean, the array is filled with aliveCells with randomly position of array[i][j].

Then, i have made this function in order to count each alive cell around one cell.

public void afficherUpdate(){

        AliveCell cellNew = new AliveCell(1,"X");
        AliveCell cellBorn = new AliveCell(1, "B");
        EmptyCell emptyCell = new EmptyCell("");
        int count = 0;
    for(int i = 0; i < this.myWorld.length -1; i++) {
            for(int j = 0; j < this.myWorld.length -1; j++) {

                 if(this.myWorld[i][j] == cellNew && i > 0 && i < 50 && j > 0 && j < 50) {
                        if(this.myWorld[i][j] == cellNew){
                            count++;
                        }
                        if(this.myWorld[i][j-1] == cellNew) {
                            count++;
                        }
                        if(this.myWorld[i-1][j] == cellNew) {
                            count++;
                        }
                        if(this.myWorld[i-1][j+1] == cellNew) {
                            count++;
                        }
                        if(this.myWorld[i-1][j-1] == cellNew) {
                            count++;
                        }
                        if(this.myWorld[i+1][j+1] == cellNew) {
                            count++;
                        }
                        if(this.myWorld[i+1][j-1] == cellNew) {
                            count++;
                        }
                        if(this.myWorld[i+1][j] == cellNew) {
                            count++;
                        }
                 }
                        System.out.println(count);

                if(this.myWorld[i][j] == emptyCell && i > 0 && i < 50 && j > 0 && j < 50) {
                    if(this.myWorld[i][j+1] == cellNew){
                        count++;
                    }
                    if(this.myWorld[i][j-1] == cellNew) {
                        count++;
                    }
                    if(this.myWorld[i-1][j] == cellNew) {
                        count++;
                    }
                    if(this.myWorld[i-1][j+1] == cellNew) {
                        count++;
                    }
                    if(this.myWorld[i-1][j-1] == cellNew) {
                        count++;
                    }
                    if(this.myWorld[i+1][j+1] == cellNew) {
                        count++;
                    }
                    if(this.myWorld[i+1][j-1] == cellNew) {
                        count++;
                    }
                    if(this.myWorld[i+1][j] == cellNew) {
                        count++;
                    }
                    System.out.println(count);
                }
                        if(myWorld[i][j] == cellNew  && count == 2 || count ==  3){
                            this.myWorld[i][j] = cellBorn;      
                        }
                        if(myWorld[i][j] == emptyCell && count== 3) {
                        this.myWorld[i][j] = cellBorn;

                        }
                 }
            }

However, the count variable returns only 0; It cannot count the alive cells around. I really don't understand why this is not working.

Thank you for your replies.

Answer 1

what you want to check is myWorld[i][j] instanceOf AliveCell

== in java is checking if the objects are same instance not equal