If you're using a recent version of the C# compiler, you might want to consider local functions: Local functions (C# Programming Guide) | Microsoft Docs[^] Using the function from the blog post that Eddy linked to, it works almost without change:
int Fib(int n) => n > 1 ? Fib(n - 1) + Fib(n - 2) : n;
Console.WriteLine(Fib(6)); // displays 8
(Of course, the best solution for calculating Fibonacci numbers is to avoid recursion. :) )
"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer
