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Is there any reason to use [] over Array.new or vice versa? Is there a
performance benefit? Is there any convention in this area? What about
{} versus Hash.new?

Thanks!

I can't directly answer your question, but something to consider is
that Ruby has *numerous* ways to do the same thing. Just look in the
documentation for the different ways to denote strings. I haven't
tested it, but I tend to think that these options don't differ much in
performance.

I completely forgot about strings. Any suggestions in that area are
welcome as well.

I am familiar with the Perl approach (whatever that long acronym is) of
having lots of ways to do things. I heard about a study of different
people's Perl code where you actually end up with different dialects.
Beginners can write code fairly easily by using a dialect they are
comfortable with. However, it took a Perl expert to understand code in
someone else's dialect.

As much as convenient, I would like to make my Ruby code readable by
the majority of other Ruby coders (and non-Ruby coders?). So I am
interested in following any good conventions. (Is there a good source
of conventions and idioms for Ruby?). And if I can get a free
performance boost by using a different idiom, I'm all for it.

Thanks!

Ryan Hinton wrote:
> Is there any reason to use [] over Array.new or vice versa? Is there a
> performance benefit? Is there any convention in this area? What about
> {} versus Hash.new?
>
> Thanks!

Array.new and Array.[] are pretty much totally different. Same for {}
and Hash.new. I think the convention is to read the docs and use them
where appropriate

-Charlie

I wouldn't worry about the performance in your example too much. If you
are worried anyway you can monkey w/ the 'Benchmark' module (the docs,
at www.ruby-doc.org/core, give examples).

maybe something like this maybe?:

require 'benchmark'
puts Benchmark.measure { 100_000.times { Array.new() } }
puts Benchmark.measure { 100_000.times { [] } }

Regarding conventions/idioms, here are just a few links to get you
started, I'm sure there are many more if you look around a bit.
http://www.rubygarden.org/ruby?RubyStyleGuide
http://www.rubygarden.org/ruby?RubyIdioms
http://www.rubygarden.org/ruby?Examp...PatternsInRuby
http://pleac.sourceforge.net/pleac_ruby/

Another good way to learn good ruby coding is to look at well written
ruby code (the ruby core, rails, etc.).

Good luck,
zak

Thanks for the excellent suggestions. At least on my machine (Pentium
M laptop, 512 MB RAM) Array.new() and Hash.new() take 50% to 100%
longer than [] and {}. Consequently, I will prefer the latter notation
for now. I think I have read most of the pages you referenced, but I
haven't delved into the core or Rails yet. I have kept an eye on the
Ruby quiz, though, from which I've gleaned some good tidbits. Thanks
again!