using System;

using System.Linq;

​

namespace ConsoleApplication1

{

    public class Program

    {

        public static void Main(string[] args)

        {

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

            int[] B = { 3, 4, 5, 6 };

​

            var resultOfUnion = A.Union(B);

​

            var resultOfConcat = A.Concat(B);

​

            Console.WriteLine("Union result");

            foreach (var item in resultOfUnion)

            {

                Console.WriteLine("\t" + item);

            }

​

            Console.WriteLine("\nConcat result");

            foreach (var item in resultOfConcat)

            {

                Console.WriteLine("\t" + item);

            }

        }

    }

}