[dragonwriter]

> I disagree that it maps most directly to the problem statement. You're performing a common factor computation in your mind, which may be more difficult given numbers other than 3 and 5.

Well, sure, explicitly calling out i % 15 rather than (i % 3) && (i % 5) or the equivalent has that problem.

> In my opinion, pattern matching offers the most direct solution and comes with an abundance of compiler optimizations.

Pattern matching is not available in many languages, but, sure, where its available, its a great choice. Note that this still has a distinct case for the case where both % 3 and % 5 are true, rather than just testing those cases independently and sequentially and concatenating, so I think it falls into the general class of solutions I was describing.

[icedog]

I'll take an extra branch over concatenation and dealing with new line chars any day.