Most efficent way of joining strings

Question

I need to concatenate a lot of strings alltogether and put a comma between any of them. I have a list of strings

\"123123123213\"
\"1232113213213\"
\"1232131         


        

Answer 1

Test code:

public static void Performance(Action fn)
{
    var timer = new Stopwatch();
    timer.Start();

    for (var i = 0; i < 10000000; ++i)
    {
        fn();
    }

    timer.Stop();

    Console.WriteLine("{0} Time: {1}ms ({2})", fn.ToString(), timer.ElapsedMilliseconds, timer.ElapsedTicks);
}

static void Main(string[] args)
{
    var stringList = new List() {
        "123123123213",
        "1232113213213",
        "123213123"
    };

    string outcome = String.Empty;
    Performance(() =>
    {
        outcome = string.Join(",", stringList);
    });

    Console.WriteLine(outcome);

    Performance(() =>
    {
        StringBuilder builder = new StringBuilder();
        stringList.ForEach
            (
                val =>
                {
                    builder.Append(val);
                    builder.Append(",");
                }
            );
        outcome = builder.ToString();
        outcome = outcome.Substring(0, outcome.Length - 1);
    });

    Console.WriteLine(outcome);

    Console.ReadKey();

}

Result 1. String.Join - 2. StringBuilder + SubString. ####ms (ticks)

In this case String.Join is faster, but if you are ok with a trailing , then

StringBuilder is slightly faster (with a trailing ,).