I think something on these lines would be a better statement of the ‘FizzBuzz’ problem.
So. if the 3rd condition was just: if your number is a multiple of 15 say 15.
Then, 3 (instead of 15) is not a wrong answer, as the last part was not explicitly spelled out.
Incomplete business problem definition :)

One important part of the original post I think everyone is missing, especially the TDD responses, is that the interviewee is expected to write the code on paper, obviously not being able to execute it before submitting it.

That would certainly make me respect the question and take my time writing my solution! I remember questions like these on Uni exams were the downfall of many.

If you ask me to submit code without compilation/execution I start to get nervous, and I think for obvious reasons – several of the above responses had simple errors that would have meant they failed the test if they didn’t see the code run first before handing it over for examination.

((0 i.~15 3 5|]){::’FizzBuzz’;'Fizz’;'Buzz’;”:)”0>:i.100

Now, even when I do a throwaway or one-time-use program, I write a small test suite checking the boundaries, possible errors in logic, etc. It’s a good way to get into TDD.

You’re right, I guess there is always a way to turn even a relatively trivial question into a more complex one, you just need to be creative and know what you’re trying to find out.

1.upto(100) { |n| puts n % 3 == 0 ? n % 5 == 0 ? “fizzbuzz” : “buzz” : n % 5 == 0 ? “fizz” : n }

But it’s not necessarily the question itself that matters, it’s what you get from the interviewee’s answer – the if/elsif solution given (and my short one above, for that matter) contains some duplication, for example (tests for modulus 3 or 5, repetition of “fizz” and “buzz”) . So a the reaction to a followup question such as “how might you refactor that?” might be informative, or “how would you minimise the locus of change if I introduced ‘foo’ for 7, or wanted an arbitrary set of numbers and words?”

If asked to refactor, I might write something like the following. I may also comment that it’s probably overkill in this relatively trivial case but I’d hope to show that I have some grasp of advanced (?) concepts like DRY and refactorings such as Extract Method.

def fizzbuzz(n)
fb_string = [[3,'fizz'],[5,'buzz']].inject(”) do |output, fb|
divisor, replacement = fb
output << ( n % divisor == 0 ? replacement : '' )
end
fb_string.size == 0 ? n : fb_string
end
(1..100).each { |n| p fizzbuzz(n) }

I might also comment that, should it be worthwhile to really hone the code, I would like to try simplifying more to remove the temporary string assignment and size check.