Format String

using System;
using System.Linq

public static class StringExtensions
{
 public static string Format(this string format, object arg, params object[] additionalArgs)
 {
 if (additionalArgs == null || additionalArgs.Length == 0)
 {
 return string.Format(format, arg);
 }
 else
 {
 return string.Format(format, new object[] { arg }.Concat(additionalArgs).ToArray());
 }
 }
}

string greeting = "Hello {0}, my name is {1}, and I own you."

Console.WriteLine(greeting.Format("Adam", "Microsoft"))