using System.Diagnostics;
public static void Main()
string a = new String('a', 10000);
string b = new String('b', 15000);
Stopwatch stopWatch = new Stopwatch();
string joinedString = null;
var builder = new StringBuilder(a);
Console.WriteLine(stopWatch.Elapsed);
Console.WriteLine(stopWatch.Elapsed);
result = String.Compare(joinedString, c, false) == 0;
Console.WriteLine(stopWatch.Elapsed);
result = joinedString.Equals(c, StringComparison.CurrentCultureIgnoreCase);
Console.WriteLine(stopWatch.Elapsed);