.NET

To Remove Duplicates From List can be done by many different ways. You can use Distinct extension method to remove duplicates.

Below program that removes duplicates from the list in C#.

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

class Program
{
    static void Main()
    {
       // List having duplicate integer elements.
       List<int> list = new List<int>();
       list.Add(7);
      list.Add(2);
       list.Add(5);
      list.Add(5);
       list.Add(2);
       list.Add(3);
      list.Add(7);

       // Get distinct elements and convert again into a list.
       List<int> distinct = list.Distinct().ToList();

      foreach (int value in distinct)
       {
           Console.WriteLine("Distinct : {0}", value);
       }
    }
}

OR

You can use LINQ to object to remove duplicates from list,

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

class Program
{
    static void Main()
    {
        // List having duplicate string elements.
        List<string> list = new List<string>();
        list.Add("A");
        list.Add("A");
        list.Add("C");
        list.Add("D");
        list.Add("B");
        list.Add("A");
        list.Add("E");
        list.Add("E");

        // Get distinct elements.
       var distinct = (from item in list orderby item select item).Distinct();

        foreach (string value in distinct)
        {
             Console.WriteLine("Distinct : {0}", value);
        }
    }
}

Example 1: Sort Int[] Array
This example int[] array that you have in your C# program. You can call static Array.Sort Method and use it to sort a integer array in place. The result is an ascending order of numbers.

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

class Program
{
        static void Main(string[] args)
        {

               int[] data = { 999,9,19,555,5,18,399};
               Array.Sort(data);

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

               Console.ReadLine();
        }
}

Example 2: Sort string[] Array
This example string[] array that you have in your C# program. You can call static Array.Sort Method and use it to sort a string array in place. The result is an alphabetical sort.

using System;

class Program
{
    static void Main()
    {
             string[] str = new string[]
             {
                   "British",
                   "Indian",
                   "American",
                   "Chinese",
                   "Malaysians"
            };
             Array.Sort(str);

              foreach (string s in str)
                       Console.WriteLine(s);

              Console.ReadLine();
}

Example 3: Sort string Array with LINQ
This example string[] array that you have in your C# program. You can call static Array.Sort Method and use it to sort a string array in place. The result is an alphabetical sort. We will use LINQ query expression to order its contents.

using System;
using System.Linq;

class Program
{
    static void Main()
    {
             string[] str = new string[]
             {
                     "British",
                     "Indian",
                     "American",
                     "Chinese",
                     "Malaysians"
             };
             var sort = from s in str
                              orderby s
                               select s;

             foreach (string c in sort)
                   Console.WriteLine(c);

             Console.ReadLine();
    }
}

Example 4: Sort string Array in reverse using LINQ
This example string[] array that you have in your C# program. You can call static Array.Sort Method and use it to sort a string array in place. The result is an alphabetical decending sort. We will use LINQ query expression to order its contents.

using System;
using System.Linq;

class Program
{
    static void Main()
    {
              string[] str = new string[]
              {
                    "British",
                    "Indian",
                    "American",
                    "Chinese",
                    "Malaysians"
               };
               var desc = from s in str
                                   orderby s descending
                                   select s;

               foreach (string s in desc)
                       Console.WriteLine(s);

               Console.ReadLine();
    }
}

Example 5: Sort List
List<string> is a generic List collection of strings. It is stored as a string array. We can use LINQ exact same way we used in Example 3 and 4.

using System;
using System.Collections.Generic;class Program
{
    static void Main()
    {
              List<string> lst = new List<string>()
             {
                      "British",
                      "Indian",
                      "American",
                      "Chinese",
                      "Malaysians"
              };
              lst.Sort();
              foreach (string s in lst)
                    Console.WriteLine(s);

              Console.ReadLine();
    }
}

.NET

Remove Duplicates From List in C#

Sort Integer and String Array in C#