Following recursive function (function calls itself) written in C# calculates a Fibonacci Number:
static int Fibonacci (int x)
{
Console.WriteLine ("x = {0}", x);
if (x <= 1)
{
return 1;
}
return Fibonacci (x-1) + Fibonacci (x-2);
}
static void Main( )
{
Console.WriteLine ("Fibonacci no. = {0}", Fibonacci (5));
Console.ReadKey();
}