From: William James <w_a_x_man@...>
Date: 2005-11-26T08:47:27+09:00
Subject: Re: Faster way to pick the every other array member?

Damphyr wrote:
> we have [1,2,3,4,5,6,7] and want [2,4,6]
>
> Is there a way other than
>
> fields=[1,2,3,4,5,6,7]
> fields.collect!{|f|
> 	f if fields.index(f)%2==1
> }.compact!

fields.values_at( 1,3,5 )

or

fields.values_at( *Array.new(fields.size/2){|i|i*2+1} )