String comparison using different implementation and its results

gistfile1.cs

using System;
using System.Diagnostics;

namespace ConsoleApplication1
{
    class Program
    {
        const string PostcodeSubstitute = "PJ15 8JJ";
        const string MatchingPostcode = "PJ15 8QJ";

        static void Main(string[] args)
        {

            var searchText = new []{"PJ15 8QJ","PJ15 8qj ","PJ15 8qj", "PJ158QJ"};
            

            Console.WriteLine();
            var sw = new Stopwatch();

            Setup(sw);
            UseStringEquals(searchText);
            Report(sw);

            Setup(sw);
            UseStringEqualsOrdinalIgnoreCase(searchText);
            Report(sw);

            sw.Start();
            UseIfComparision(searchText);
            Report(sw);
            
            sw.Start();
            UsingEquals(searchText);
            Report(sw);
       
            sw.Start();
            UsingCompareTo(searchText);
            Report(sw);


            Console.ReadKey();
        }

        private static void Setup(Stopwatch sw)
        {
            sw.Start();
        }

        private static void Report(Stopwatch sw)
        {
            sw.Stop();

            Console.WriteLine("Elapsed time: {0} ticks| {1} milisec", sw.ElapsedTicks, sw.ElapsedMilliseconds);
            Console.WriteLine();
            sw.Reset();
        }


        /// <summary>
        /// Results:
        ///     Original: PJ15 8QJ | New: PJ15 8JJ
        ///     Original: PJ15 8qj  | New: PJ15 8JJ
        ///     Original: PJ15 8qj | New: PJ15 8JJ
        ///     Original: PJ158QJ | New: PJ158QJ
        ///     Elapsed time: 2157 ticks| 0 milisec
        /// </summary>
        /// <param name="postcodes"></param>
        public static void UseStringEquals( string[] postcodes)
        {
            foreach (var postcode  in postcodes)
            {
                string code = postcode;
                
                if (string.Equals(postcode.Trim(), MatchingPostcode, StringComparison.CurrentCultureIgnoreCase))
                {
                     code = PostcodeSubstitute;
                }

                Console.WriteLine("Original: {0} | New: {1}", postcode, code);    
            }
        }       

        /// <summary>
        /// Results:
        ///         Original: PJ15 8QJ | New: PJ15 8JJ
        ///         Original: PJ15 8qj  | New: PJ15 8JJ
        ///         Original: PJ15 8qj | New: PJ15 8JJ
        ///         Original: PJ158QJ | New: PJ158QJ
        ///         Elapsed time: 910 ticks| 0 milisec
        /// </summary>
        /// <param name="postcodes"></param>
        public static void UseStringEqualsOrdinalIgnoreCase( string[] postcodes)
        {
            foreach (var postcode  in postcodes)
            {
                string code = postcode;
                
                if (string.Equals(postcode.Trim(), MatchingPostcode, StringComparison.OrdinalIgnoreCase))
                {
                     code = PostcodeSubstitute;
                }

                Console.WriteLine("Original: {0} | New: {1}", postcode, code);    
            }
        }

        /// <summary> 
        /// Results:
        /// Original: PJ15 8QJ | New: PJ15 8JJ
        ///     Original: PJ15 8qj  | New: PJ15 8JJ
        ///     Original: PJ15 8qj | New: PJ15 8JJ
        ///     Original: PJ158QJ | New: PJ158QJ
        ///     Elapsed time: 855 ticks| 0 milisec

        /// </summary>
        /// <param name="postcodes"></param>
        public static void UsingCompareTo(string[] postcodes)
        {
            foreach (var postcode in postcodes)
            {
                string code = postcode.Trim().ToUpperInvariant();

                if (code.CompareTo(MatchingPostcode.ToUpperInvariant()) == 0) // beware: 0 means equality
                {
                    code = PostcodeSubstitute;
                }

                Console.WriteLine("Original: {0} | New: {1}", postcode, code);
            }
        } 

        /// <summary>
        /// Results:
        ///    Original: PJ15 8QJ | New: PJ15 8JJ
        ///     Original: PJ15 8qj  | New: PJ15 8JJ
        ///     Original: PJ15 8qj | New: PJ15 8JJ
        ///     Original: PJ158QJ | New: PJ158QJ
        ///     Elapsed time: 951 ticks| 0 milisec
        /// </summary>
        /// <param name="postcodes"></param>
        public static void UseIfComparision(string[] postcodes)
        {
            foreach (var postcode in postcodes)
            {
                string code = postcode.Trim().ToUpperInvariant();
                if (code == MatchingPostcode.ToUpperInvariant())
                {
                    code = PostcodeSubstitute;
                }

                Console.WriteLine("Original: {0} | New: {1}", postcode, code);    
            }
        }

        /// <summary>
        /// Results:
        /// Original: PJ15 8QJ | New: PJ15 8JJ
        ///     Original: PJ15 8qj  | New: PJ15 8JJ
        ///     Original: PJ15 8qj | New: PJ15 8JJ
        ///     Original: PJ158QJ | New: PJ158QJ
        ///     Elapsed time: 976 ticks| 0 milisec
        /// </summary>
        /// <param name="postcodes"></param>
        public static void UsingEquals(string[] postcodes)
        {
            foreach (var postcode in postcodes)
            {
                string code = postcode.Trim().ToUpperInvariant();
                if (Equals(code, MatchingPostcode.ToUpperInvariant()))
                {
                    code = PostcodeSubstitute;
                }

                Console.WriteLine("Original: {0} | New: {1}", postcode, code);    
            }
        }  
    }
}