Two Dimensional Array in Java.

Arrays with two sets of square brackets [][] are called two-dimensional arrays. A two dimensional array is used when data items are arranged in row-wise and column-wise in a tabular form. The array has two sets of square brackets [3][4], and hence it is a 2 dimensional array with 3 rows and 4 columns. This declaration informs the compiler to reserve 12 locations(3*4=12)contiguously one after the other.

Initialization of two dimensional array.

Assigning required value to a variable before processing is initialization. As we initialize a variable to the required value we can initialize the individual elements of a 2 dimensional array during initialization.

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

        // create a 2d array
        int[][] a = {
            {1, 2, 3}, 
            {4, 5, 6, 9}, 
            {7}, 
        };
      
        // calculate the length of each row
        System.out.println("Length of row 1: " + a[0].length);
        System.out.println("Length of row 2: " + a[1].length);
        System.out.println("Length of row 3: " + a[2].length);
    }
}