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

According to the following test I've made, Join is 3x faster faster on large arrays:

The Text.txt file contains the value "aaaaaaaaaaaaaaaaaaa" on 38400 lines:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Diagnostics;

namespace ConsoleApplication1
{
  class Program
  {
    static void Main(string[] args)
    {
      var strings = File.ReadAllLines("Text.txt");

      Stopwatch sw;

      StringBuilder sb = new StringBuilder();

      sw = Stopwatch.StartNew();
      for (int i = 0; i < strings.Length; i++)
      {
        sb.AppendLine(strings[i]);
      }
      sw.Stop();
      TimeSpan sbTime = sw.Elapsed;

      sw = Stopwatch.StartNew();
     var output = string.Join(",", strings);
     sw.Stop();

     TimeSpan joinTime = sw.Elapsed;   

    }
  }
}

Output:

00:00:00.0098754
00:00:00.0032922