using System;

using System.Linq;

using System.Collections.Generic;

using System.Threading.Tasks;

static public class ExtensionMethods

{

    public static IEnumerable<T> ToSingleDimension<T>(this T[,] source)

    {

        for (int i=0; i<=source.GetUpperBound(1); i++)

        {

            for (int j=0; j<=source.GetUpperBound(0); j++)

            {

                yield return source[j,i];

            }

        }

    }

}

​

public class Program

{

    public static void Main()

    {

        int[,] result = new int[2, 5];

        result[0,0] = 00;

        result[0,1] = 01;

        result[0,2] = 02;

        result[0,3] = 03;

        result[0,4] = 04;

        result[1,0] = 10;

        result[1,1] = 11;

        result[1,2] = 12;

        result[1,3] = 13;

        result[1,4] = 14;

        var resultArray1 = result.Cast<int>().Select( n => n.ToString("00")).ToArray();

​

        var resultArray2 = result.ToSingleDimension().Select( n => n.ToString("00")).ToArray();

        Console.WriteLine("Using default LINQ logic:");

        foreach (var r in resultArray1) Console.WriteLine("{0}", r);

​

        Console.WriteLine("Using extension method logic:");

        foreach (var r in resultArray2) Console.WriteLine("{0}", r);

    }

}