gistfile1.txt

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
using System;
using System.Text;

namespace ConsoleApplication1
{
    public class Program
    {
        private StringBuilder sb = new StringBuilder();
        private string expected;

        [Params(100, 1000, 5000)]
        public int N;

        [GlobalSetup]
        public void Setup()
        {
            for (int i = 0; i < N; i++)
            {
                sb.Append(new string('x', 50));
            }

            expected = sb.ToString();
        }

        public static void Main(string[] args)
        {
            var summary = BenchmarkRunner.Run<Program>();
        }

        [Benchmark]
        public bool ToStringFirst()
        {
            // Console.WriteLine(Object.ReferenceEquals(a, b)); // returns false

            return (expected == sb.ToString());
        }

        [Benchmark]
        public bool IndexedBackward()
        {
            if (expected.Length != sb.Length) return false;

            for (int i = expected.Length - 1; i >= 0; i--)
            {
                if (expected[i] != sb[i])
                {
                    return false;
                }
            }

            return true;
        }


        [Benchmark]
        public bool IndexedForward()
        {
            if (expected.Length != sb.Length) return false;

            for (int i = 0; i < expected.Length ; i++)
            {
                if (expected[i] != sb[i])
                {
                    return false;
                }
            }

            return true;
        }
    }
}