static void RectMultidimensionalArray()
        {
            Console.WriteLine("=> Rectangular multidimensional array: ");
            // A rectangular multidimensional array.
            int[,] myMatrix;
            myMatrix = new int[3, 4];

            // Populate (3 * 4) array.
            for(int i = 0; i < 3; i++) // Why there are no curly braces?
            for(int j = 0; j < 3; j++) // Why there are no curly braces?
            myMatrix[i,j] = i + j;

            // Print (3 * 4) array.
            for (int i = 0; i < 3; i++)
            {
                for (int j = 0; j < 4; j++)
                    Console.WriteLine(myMatrix[i,j] + "\t");
                Console.WriteLine();
            }
            Console.WriteLine();
        }

        static void RectMultidimensionalArray2()
        {
            Console.WriteLine("=> Rectangular multidimensional array: ");
            // A rectangular multidimensional array.
            int[,] myMatrix;
            myMatrix = new int[3, 4];

            // Populate (3 * 4) array.
            for (int i = 0; i < 3; i++)
            {
                for (int j = 0; j < 3; j++)
                {
                    myMatrix[i, j] = i + j;
                }
            }

            // Print (3 * 4) array.
            for (int i = 0; i < 3; i++)
            {
                for (int j = 0; j < 4; j++)
                    Console.WriteLine(myMatrix[i, j] + "\t");
                Console.WriteLine();
            }
            Console.WriteLine();
        }