Colin has a nice little quiz about enumeration on his blog. Basically he asks, how would you implement a class to enumerate through all the letters of the alphabet. Below is my “cute” response.

using System;
using System.Collections;
 
public class Alphabet : IEnumerable
{
  public IEnumerator GetEnumerator()
  {
    return "abcdefghijklmnopqrstuvwxyz".GetEnumerator();
  }
}

Now if you compile my answer and run it, it seems to answer the question correctly (for an academic quiz), but it’s completely wrong for a real world developer. The right answer is “Well, which alphabet or alphabets must I support? Does it need to be localizable based on the current locale?”.

Yes my friends, the answer is to gather more requirements. Make sure you really understand the problem domain. This is why software isn’t as easy as “well I want it to do this so just do it.” This quiz asks what seems to be a very straightforward question. If you as a developer gave me the solution I wrote above, I’d be pretty pissed as a client if I was ready to deploy this to Korea.