如何在我的 getCell 方法中访问元胞数组？ （爪哇）

Question

my Task is to make an implementation of Conway's Game of Life. Therefor I need to create the class GameMap. In this class I will initialize an 2D Array. Therefor I use those two methods.

private static Cell[][] buildCellArray(int width, int height){
        Cell[][] cellArray = new Cell[width][height];
        int i;
        int j;
        for(i = 0; i < width; i++) {
            for(j = 0; j < height; j++) {
                cellArray[i][j] = new Cell();
            }
        }
        return cellArray;
    }
    
    public GameMap(int sizeX, int sizeY) {
        buildCellArray(sizeX, sizeY);
    }

Now I want to access the cellArray to access a special Cell with the getCell(int posX, int posY) method. My question is how I can access the cellArray? I wanted to access it like this:

public Cell getCell(int posX, int posY){
        return cellArray[posX][posY];
    }

So that I get the Cell at a special position. I hope somebody can help me out.

So the complete code part is:

public class GameMap {
    private static Cell[][] buildCellArray(int width, int height){
        Cell[][] cellArray = new Cell[width][height];
        int i;
        int j;
        for(i = 0; i < width; i++) {
            for(j = 0; j < height; j++) {
                cellArray[i][j] = new Cell();
            }
        }
        return cellArray;
    }
    
    public GameMap(int sizeX, int sizeY) {
        buildCellArray(sizeX, sizeY);
    }
    
    
    public Cell getCell(int posX, int posY){
        return cellArray[posX][posY];
    }
}

And the IDE says that cellArray in the method getCell is not a variable.

Answer 1

The IDE says cellArray cannot be resolve to a variable because it is local variable, to pass this problem just move Cell[][] cellArray = new Cell[width][height]; outside the buildCellArray() .

public class GameMap {

    Cell[][] cellArray;

    private static Cell[][] buildCellArray(int width, int height){
        int i;
        int j;

        for(i = 0; i < width; i++) {
            for(j = 0; j < height; j++) {
                cellArray[i][j] = new Cell();
            }
        }
    
        return cellArray;
    }
    
    public GameMap(int sizeX, int sizeY) {
         buildCellArray(sizeX, sizeY);
    }

    public Cell getCell(int posX, int posY){
        return cellArray[posX][posY];
    }
}