Console application to test concatenation performance of a string compared with using StringBuilder. Program prompts for string and amount of times to concatenate.

Program.cs

using System;
using System.Text;
using System.Diagnostics;

namespace StringBuilderTest
{
    class Program
    {
        static void Main(string[] args)
        {
            var userQuit = false;
            do
            {
                int concatTimes;
                Console.Write("Enter string to concatenate: ");
                string userInput = Console.ReadLine();

                Console.Write("Times to concatenate: ");
                if (!int.TryParse(Console.ReadLine(), out concatTimes) || concatTimes < 0)
                {
                    Console.WriteLine("Please enter a number greater than 0!");
                    Console.WriteLine();
                    continue;
                }
                Console.WriteLine("-----------------------------------------------");
                string appended = "";
                var swTest = new Stopwatch();
                Console.WriteLine("Beginning concatenation test...");
                swTest.Start();
                for (int i = 0; i < concatTimes; i++)
                {
                    appended += userInput;
                }
                // Console.WriteLine(appended);
                swTest.Stop();
                Console.WriteLine("Concatenation test finished!");
                Console.WriteLine(string.Format("Results in seconds: {0}", swTest.Elapsed.TotalSeconds));
                Console.WriteLine(string.Format("Results in ms: {0}", swTest.Elapsed.TotalMilliseconds));
                Console.WriteLine();

                Console.WriteLine("Beginning StringBuilder test...");
                var built = new StringBuilder();
                swTest.Restart();
                for (int i = 0; i < concatTimes; i++)
                {
                    built.Append(userInput);
                }
               //  Console.WriteLine(built);
                swTest.Stop();
                Console.WriteLine("StringBuilder test finished!");
                Console.WriteLine(string.Format("Results in seconds: {0}", swTest.Elapsed.TotalSeconds));
                Console.WriteLine(string.Format("Results in ms: {0}", swTest.Elapsed.TotalMilliseconds));
                Console.WriteLine("-----------------------------------------------");
                Console.WriteLine();

            } while (userQuit == false);
        }
    }
}