How can you sort the elements of the array in descending order?

It depends whether you want the sort to be permanent or not:

using System;

using System.Collections.Generic;

using System.Linq;

class Test

{

static void Main()

{

int[] ia = {1, 2, 3, 4};

// permanent reverse order sort

Array.Sort(ia);

Array.Reverse(ia);

foreach(int i in ia) Console.WriteLine(i);

Console.WriteLine();

// temporary reverse order sort

int[] ia2 = {5, 6, 7, 8};

IEnumerable ie = from i in ia2 orderby i descending select i;

foreach(int i in ie) Console.WriteLine(i);

Console.WriteLine();

// order of ia2 unaffected

foreach(int i in ia2) Console.WriteLine(i);

Console.ReadKey();

}