StopWatch

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace GB
{
    class Book
    {
        public string Title { get; set; }
        public string Author { get; set; }
        public string Genre { get; set; }
        public bool IsFiction { get; set; }

    }


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



            Stopwatch stopwatch = new Stopwatch();

            stopwatch.Start();
          
            string numbers = "";
            for (int i = 0; i < 1000; i++)
            {
                numbers += i;
            }

            stopwatch.Stop();

            Console.WriteLine("Time Elapsed: {0}", stopwatch.Elapsed);

            stopwatch.Reset();
            stopwatch.Start();
            StringBuilder sb = new StringBuilder();

            for (int i = 0; i < 1000; i++)
            {
                sb.Append(i);
            }
            //Console.WriteLine(sb.ToString());

            stopwatch.Stop();
            Console.WriteLine("Time Elapsed: {0}", stopwatch.Elapsed);


            Console.ReadLine();

        }
    }
}