I created the convenience functions "multiple_of_3" and "multiple_of_5" for a couple of reasons:
1. To make it clear to the interviewer that I "get" the problem.
2. To prevent myself from making any dumb mistakes. I'm only a half-decent coder, so I've made it a habit of putting such "Mollyguards" (http://en.wiktionary.org/wiki/molly-guard) in my code as a precaution.
3. To show a little Ruby coding style. The convention in Ruby is to favour lots of concise little routines over big-ass ones. See "Eloquent Ruby" for the guideline and Shopify's ActiveMerchant library for an example of such Ruby in actual production code.
> To show a little Ruby coding style. The convention in Ruby is to favour lots of concise little routines over big-ass ones.
Writing small, concise components(classes, methods, functions, modules...) is a generally a good practice in any language. However, moving i % 3 in a separate method is not a good practice. As another commenter pointed out, your names are hardly apt. It would better serve to name them fizz?(multiple_of_3) and buzz?(multiple_of_5). But even then, if all fizz? is doing is i % 3, let it be inline. True that in the future you might need additional processing for fizz?(not for this particular eg; I am talking real world), but re-factor it when you need it. It's not like if you have i%3 inline, it makes it harder to re-factor it into a fizz? method later.
Also, since you are talking ruby conventions, shouldn't your predicates be named multiple_of_3? instead of multiple_of_3?
1. To make it clear to the interviewer that I "get" the problem. 2. To prevent myself from making any dumb mistakes. I'm only a half-decent coder, so I've made it a habit of putting such "Mollyguards" (http://en.wiktionary.org/wiki/molly-guard) in my code as a precaution. 3. To show a little Ruby coding style. The convention in Ruby is to favour lots of concise little routines over big-ass ones. See "Eloquent Ruby" for the guideline and Shopify's ActiveMerchant library for an example of such Ruby in actual production code.