MultiDimensional Arrays

The simplest multidimensional array is a two dimensional array. You can think of a two dimensional array as a simple sort of table with columns and rows. The first dimension is the number of rows and the second dimension is the number of columns.

Here is an example of a two dimensional string array that keeps track of book titles and authors. It has 3 rows and 2 columns

 string[,] books = new string[3, 2];
           
            books[0, 0] = "War and Peace";
            books[0, 1] = "Tolstoy";
            books[1, 0] = "Lord of the Rings";
            books[1, 1] = "Tolkein";
            books[2, 0] = "Huckleberry Finn";
            books[2, 1] = "Twain";

Here is an example of a two dimensional array with 3 rows and 3 columns. Think of it as containing the height, width and length of a set of boxes

int[,] boxes = new int[3, 3];
            boxes[0, 0] = 4;
            boxes[0, 1] = 2;
            boxes[0, 2] = 3;
            boxes[1, 0] = 2;
            boxes[1, 1] = 2;
            boxes[1, 2] = 1;
            boxes[2, 0] = 3;
            boxes[2, 1] = 2;
            boxes[2, 2] = 5;

It is also possible to have arrays with more than two dimensions. Below is a three dimensional array.

int[, ,] space = new int[2, 2, 2];

            space[0, 0, 0] = 5;
            space[0, 0, 1] = 4;
            space[0, 1, 0] = 3;
            space[0, 1, 1] = 4;
            space[1, 0, 0] = 3;
            space[1, 0, 1] = 6;
            space[1, 1, 0] = 2;
            space[1, 1, 1] = 5;
            space[2, 0, 0] = 3;
            space[2, 0, 1] = 6;
            space[2, 1, 0] = 2;
            space[2, 1, 1] = 5;

Arrays can have more than 3 dimensions, but they rapidly get difficult to manage.

To display a multidimensional array, you access its indexes just as in an one dimensional array. Below is the full program that creates these arrays and displays all but the last one. If you would like a little chalange, you can add code to the display method to display the contents of the 3 dimensional array.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace MultidimensionalArrays
{
    class Program
    {
        static void Main(string[] args)
        {
            Program p = new Program();
            p.Display();
            Console.ReadKey();
        }

        private string[,] TwoDimensionalArray()
        {
            //define two dimensional Array
            //first number is number of rows
            //the second is number of columns
            string[,] books = new string[3, 2];
           
            books[0, 0] = "War and Peace";
            books[0, 1] = "Tolstoy";
            books[1, 0] = "Lord of the Rings";
            books[1, 1] = "Tolkein";
            books[2, 0] = "Huckleberry Finb";
            books[2, 1] = "Twain";

            return books;
        }

        private int[,] Another2DimensionalArray()
        {
            //think of an array that holds
            //the height, width, and length
            //of boxes
            //although it has 3 columns
            //it is still a two dimensional 
            //array
            int[,] boxes = new int[3, 3];
            boxes[0, 0] = 4;
            boxes[0, 1] = 2;
            boxes[0, 2] = 3;
            boxes[1, 0] = 2;
            boxes[1, 1] = 2;
            boxes[1, 2] = 1;
            boxes[2, 0] = 3;
            boxes[2, 1] = 2;
            boxes[2, 2] = 5;

            return boxes;

        }

        private int[, ,] ThreeDimensionalArray()
        {
            //think of 3 dimensionals as a cube
            //you can do more dimensions but it
            //gets beyond absurd
            int[, ,] space = new int[2, 2, 2];

            space[0, 0, 0] = 5;
            space[0, 0, 1] = 4;
            space[0, 1, 0] = 3;
            space[0, 1, 1] = 4;
            space[1, 0, 0] = 3;
            space[1, 0, 1] = 6;
            space[1, 1, 0] = 2;
            space[1, 1, 1] = 5;
            space[2, 0, 0] = 3;
            space[2, 0, 1] = 6;
            space[2, 1, 0] = 2;
            space[2, 1, 1] = 5;

            return space;
        }

        private void Display()
        {
            //you access the values in multidimensional arrays
            //just like regular ones, through their indexes

            string[,] mybooks = TwoDimensionalArray();
            Console.WriteLine("The second book is {0}, by {1}", 
                mybooks[1, 0], mybooks[1, 1]);
            Console.WriteLine("*********************************");
            // the loop below multiplies the contents
            //of the three columns together
            int[,] cubes = Another2DimensionalArray();
            int cubicInches = 0;
            for (int i = 0; i < 3; i++)
            {
                cubicInches = cubes[i, 0] * cubes[i, 1] * cubes[i, 2];
                Console.WriteLine("Box {0}, is {1} cubic inches", i+1, cubicInches);
            }
            Console.WriteLine("*********************************");
           
        }
    }
}