From: Robert Klemme <shortcutter@...>
Date: 2008-03-21T17:54:52+09:00
Subject: Re: Dealing properly with scope; came from:combine array(string) to   string?

On 21.03.2008 08:14, Todd Benson wrote:
> On Thu, Mar 20, 2008 at 6:14 PM, Daniel Finnie <dan@danfinnie.com> wrote:
>> You can usually use inject or collect to eliminate the a = [] line.
>>  For example:
>>
>>  b = %w[a b c d e]
>>  a = b.collect {|i| i * 2 }
> 
> Unless you have a method that doesn't return an array (i.e. something
> other than map/collect).  Sometimes you have to build the array inside
> the iterator.  I was just wondering if this was common practice.

Yes, that's perfectly ok.  Often you can also use a variant using 
#inject, like

irb(main):003:0> b = %w[a b c d e]
=> ["a", "b", "c", "d", "e"]
irb(main):004:0> b.inject([]){|ar,el| ar << el*2}
=> ["aa", "bb", "cc", "dd", "ee"]

But that would be silly in this case since there is #map / #collect.

Kind regards

	robert