09 May Multidimensional Arrays in Java

In the last lesson, we learned about One-Dimensional Arrays in Java and how to use them. Now, we will see about a concept of arrays in Java i.e. Multidimensional Arrays. Multi-dimensional arrays as the name suggests are arrays of arrays. You need to use two square brackets to declare a multidimensional array, unlike one-dimensional array.

Let us see an example to declare a 2 by 3 multidimensional array,

int result[][] = new int[2][3];

The following figure displays how a multidimensional array forms a 2×3 matrix,

Above, the left index determines row and the right index determines column.

We will now see how to display each element from our 2×3 matrix,

// Two-Dimensional (2D) Array in Java
class Demo {
    public static void main(String[] args) {

        int i, j, k = 0;
        int[][] result = new int[2][3];

        for(i=0; i < 2; i++) {
            for(j=0; j < 3; j++) {
                result[i][j] = k;
                k++;
            }
        }

        for(i=0; i < 2; i++) {
            for(j=0; j < 3; j++) {
                System.out.print(result[i][j] + " ");
            }
            System.out.println();
        }
    }
}

The following is the output displaying each element,

Let us see another example:

// Two-Dimensional (2D) Array in Java

class Demo {
    public static void main(String[] args) {

        int i, j, k = 0;
        int[][] result = new int[3][3];

        for(i=0; i < 3; i++) {
            for(j=0; j < 3; j++) {
                result[i][j] = k;
                k++;
            }
        }

        for(i=0; i < 3; i++) {
            for(j=0; j < 3; j++) {
                System.out.print(result[i][j] + " ");
            }
            System.out.println();
        }
    }
}

Output

0 1 2 
3 4 5 
6 7 8 

In this lesson, we saw how to work with Multidimensional arrays in Java.