using System;

using System.Collections.Generic;

using System.Diagnostics;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

​

namespace ConsoleApp1

{

    class Program

    {

        static void Main(string[] args)

        {

​

            var dict = Enumerable.Range(1, 1000).ToDictionary(i=>i);

​

            var watch = new Stopwatch();

​

            watch.Start();

​

            foreach (var item in Enumerable.Range(1001, 2000))

            {

​

                try

                {

                    var i = dict[item];

                }

                catch (KeyNotFoundException ex)

                {

​

​

                }

​

            }

​

            watch.Stop();

​

            Console.WriteLine(watch.ElapsedMilliseconds);

​

            watch.Restart();

​

            foreach (var item in Enumerable.Range(100001, 200000))

            {

                var i = dict.TryGetValue(item, out int val);

            }

​

            watch.Stop();

​

            Console.WriteLine(watch.ElapsedMilliseconds);

​

            Console.ReadKey();

​

        }

    }

}

​