using System;

public class Program

{

    public static void Main()

    {

        //declares a rectangular two dimensional array, where the dimensions are 4 × 2

        char[,] charArray = new char[4, 2]; // 2D array

        // assign values to the elements of a rectangular array

        charArray[0, 0] = 'A';

        charArray[0, 1] = 'B';

        charArray[1, 0] = 'C';

        charArray[1, 1] = 'D';

        charArray[2, 0] = 'E';

        charArray[2, 1] = 'F';

        charArray[3, 0] = 'G';

        charArray[3, 1] = 'H';

        // OR

        // char[,]charArray = { { 'A', 'B' }, { 'C', 'D' }, { 'E', 'F' }, { 'G', 'H' } };

        // Specify the dimension and the index to fetch a value from a specific placeholder. 

        Console.WriteLine(charArray[1, 0]); // return C

        Console.WriteLine(charArray[3, 1]); // return H

        Console.WriteLine("\n**********Updated Values**********\n");

        // access a value of an indexed array element by using indexer ([  ]) and then assign a value to it with assignment operator (=). 

        charArray[1, 0] = 'K';

        charArray[3, 1] = 'L';

        // To fetch a value from a specific placeholder 

        Console.WriteLine(charArray[1, 0]); // return K

        Console.WriteLine(charArray[3, 1]); // return L

​

    }

}