Quine… er, uh.. what’s that?

That is what I said yesterday to one of my Interviewers 😉

Yesterday I had a damn good interview, four hours of what became an interesting technical conversation on mostly coding and Software architecture related topics, with some interesting challenges which I will not disclose.

But I had fun! and at the end of it, the not anymore interviewer but future colleague asked me if I knew what was a Quine… to what I had no clue so I asked.

Basically is a program that produces a copy of its own source code as its output. Without any other purpose. Apart from the “AHA” moment when you understand what is happening 😉

A simple example, create a console application and paste the following code:

namespace WelcomeTo
{
    class Program
    {
        static void Main()
        {
            string s = @"using System;
namespace WelcomeTo{{
class Zühlke{{static void Main()
{{
string s=@{0}{1}{0};
Console.Write(s,'{0}',s);
Console.ReadLine();
}}}}}}";
            Console.Write(s, '"', s);
            Console.ReadLine();
        }
    }
}

Once we execute it, we get the following result :

Which is basically the same code which generated it.

So, now is your turn to try to figure out why.

Hint: There is a very easy to catch eastern egg on it…

Thanks To Jonathan Ziller for pointing me to it.