Autor: Codenga 12.06.2023

There is nothing difficult about multidimensional arrays. Read this short article and for yourself!

Remember the game of battleships? A game board is very similar to a multidimensional array. We will show you how to declare such a board:

char[][] board;

Let's try to create a board consisting of 4 rows and 4 columns:

char[][] board = new char[4][4];

The board should be understood in this manner:

char[][] board = new char[row][column];

The array can also be initialized using the following technique. The size of the array will be calculated dynamically based on the number of elements. Doesn't a two-dimensional array remind you a bit of a battleship board? Take a look. We put ships on it to make it more clear.

public class Conversion {
    public static void main(String[] args) {
    	    
        char[][] board = {
            {' ', ' ', ' ', ' '},
            {'o', ' ', ' ', ' '},
            {'o', ' ', ' ', 'o'},
            {'o', ' ', ' ', ' '}
    	};
    }
}

Let's look at the two-dimensional array above. We have the following ships available:

• 1 single-mast ship
• 1 tri-mast ship

How do we sink our single-mast ship? The table indexes are counted from zero. Our single-mast ship is in column 3 and row 2.

We can easily calculate its position ie:

board[2][3]; //namely 'o'

It looks pretty good. Do you remember program loops? Loops and arrays can cooperate with each other perfectly. Nothing changes here. We can display the whole board very neatly. Since we have a two-dimensional array we will have to use two loops (nested loops) . A nested loop is one that is inside the body of the other loop. Here is an example:

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

      }
}

Let's use this knowledge to display our board:

public class Conversion {
    public static void main(String[] args) {
    	    
        char[][] board = {
            {' ', ' ', ' ', ' '},
            {'o', ' ', ' ', ' '},
            {'o', ' ', ' ', 'o'},
            {'o', ' ', ' ', ' '}
    	};
    	
    	for(int i = 0; i < board.length; i++) {
    	    for(int j = 0; j < board[i].length; j++) {
    	        System.out.print(board[i][j]);
    	    }
    	    
    	    System.out.println();
    	}
    }
}

The variable i is responsible for the row position, and the variable j is responsible for the column position of our game board. The nested loop is responsible for drawing the ships, and the surrounding loop is responsible for writing out new lines.

Here is the result of our work:

o
o  o
o

Yup! That’s it. As you can see, there is nothing overly difficult when it comes to using multidimensional arrays in Java.

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