A 2d array example in Java.

ArrayTest.java

public class ArrayTest {

    public static void main(String[] args) {
	final int ROW = 3;
	final int COL = 4;

        int[][] numbers = new int[ROW][COL];

        int 	total = 0,
        	value = 0;

        for (int i = 0; i < ROW; i++)
        {
		for (int n = 0; n < COL; n++)
        	{
			numbers[i][n] = value;
			value += 1;
		}
	}

        for (int i = 0; i < ROW; i++)
        {

		for (int n = 0; n < COL; n++)
        	{
			total += numbers[i][n];
        		System.out.println(numbers[i][n]);
		}
	}

		System.out.println("The total is: " + total);
    }

}