Converting a C# Two-Dimensional Array to a One-Dimensional Array

C# Array Dimension Conversion Operations

Hello everyone, in this article I will explain how you can convert between one-dimensional and two-dimensional arrays. For those of you who wonder why we might need something like this, let me briefly summarize: I have been working on a Tic-Tac-Toe game for the past two days and I used Firebase as the online infrastructure. 

Within Firebase, I was thinking of using Firestore, but unfortunately Firestore does not support multi-dimensional arrays, and it was saving the data as a one-dimensional array only. However, my data structure was multi-dimensional (2D), and therefore I needed such a conversion. 

Anyway, without making it too long and wasting your time, let's see how we can do this process.

Note: You can edit the codes below yourself and adapt them for larger arrays.

Converting a Two-Dimensional Array to a One-Dimensional Array

        public static T[] ConvertToArray<t>(T[,] matrix)
        {
            var array = matrix.Cast<t>().ToArray(); // With the help of LINQ, we convert our matrix into an array.
            return array; // We return the result.
        }
</t></t>

Converting a One-Dimensional Array to a Two-Dimensional Array

               public static T[,] ConvertToMatrix<t>(T[] array, int lenght)
        {
            if (array.Length != lenght * lenght) // We check the width of the array, will it be compatible with the matrix?
                Console.WriteLine("Invalid Lenght"); // If not compatible, we output an error message.

            var matrix = new T[lenght, lenght]; // We create our matrix.
            var counter = 0; // We create a counter to navigate inside the array.

            // The loop in which we perform the process of converting the array to the matrix.
            for(var y = 0; y < lenght; y++)
            {
                for(var x = 0; x < lenght; x++)
                {
                    matrix[y, x] = array[counter];
                    counter++;
                }
            }

            return matrix; // We return the result.
        }
</t>

All Code

using System;
using System.Linq;

namespace TestProject
{
    class MainClass
    {
        public static void Main(string[] args)
        {

            Console.WriteLine("----- Array To Matrix Start -----");

            // We create an array for testing.
            int[] numberArray = new int[9]
            {
                0,1,2,3,4,5,6,7,8
            };

            // We convert our array into a matrix.
            var numberConvertedMatrix = ConvertToMatrix<int>(numberArray, 3);

            // We print the result to the screen.
            for(int y = 0; y < 3; y++)
            {
                for (int x = 0; x < 3; x++)
                {
                    Console.Write($"{numberConvertedMatrix[y, x]}");
                }
                Console.Write("\n");

            }

            // Here we print the type of numberConvertedMatrix, i.e., our matrix variable, to the screen—it gives us int[,].
            Console.WriteLine($"{numberConvertedMatrix}");

            Console.WriteLine("----- Array To Matrix Finish -----");
            Console.WriteLine("----- Matrix To Array Start -----");

            // We create a matrix.
            int[,] numberMatrix = new int[3, 3]
            {
                {0,1,2 },
                {3,4,5 },
                {6,7,8 }
            };

            // We convert our matrix into an array. Where it says ConvertToArray<int>, you can write any variable type you want instead of <int> and use this function with that data type.
            var numberConvertedArray = ConvertToArray<int>(numberMatrix);


            // We print the result to the screen
            foreach(var number in numberConvertedArray)
            {
                Console.WriteLine($"{number}");
            }

            // Here we print the type of numberConvertedArray, i.e., our array variable, to the screen—it gives us int[].

            Console.WriteLine($"{numberConvertedArray}");
            Console.WriteLine("----- Matrix To Array Finish -----");


        }


        public static T[,] ConvertToMatrix<t>(T[] array, int lenght)
        {
            if (array.Length != lenght * lenght) // We check the width of the array, will it be compatible with the matrix?
                Console.WriteLine("Invalid Lenght"); // If not compatible, we output an error message.

            var matrix = new T[lenght, lenght]; // We create our matrix.
            var counter = 0; // We create a counter to navigate inside the array.

            // The loop in which we perform the process of converting the array to the matrix.
            for(var y = 0; y < lenght; y++)
            {
                for(var x = 0; x < lenght; x++)
                {
                    matrix[y, x] = array[counter];
                    counter++;
                }
            }

            return matrix; // We return the result.
        }

        public static T[] ConvertToArray<t>(T[,] matrix)
        {
            var array = matrix.Cast<t>().ToArray(); // With the help of LINQ, we convert our matrix into an array.
            return array; // We return the result.
        }
    }
}

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