From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2011-10-20T16:50:11+09:00
Subject: Re: Moving files into alphabetical directories

On Thu, Oct 20, 2011 at 12:43 AM, Yossef Mendelssohn <ymendel@pobox.com> wrote:
> On Oct 19, 4:47 pm, Jesús Gabriel y Galán <jgabrielyga...@gmail.com>
> wrote:
>> A way to get a hash that contains a key for each letter with an array
>> of words starting with that letter:
>>
>> h = {}
>> names.each do |name|
>>   letter = name[0,1].upcase #seems the letters must be upcased
>>   (h[letter] ||= []) << name
>> end
>
> This is a good place to use Enumerable#group_by.
>
>    >> names = %w(simon sadie tyler kirsty kevin keith)
>    => ["simon", "sadie", "tyler", "kirsty", "kevin", "keith"]
>    >> names.group_by { |n| n[0,1].upcase }
>    => {"K"=>["kirsty", "kevin", "keith"], "S"=>["simon", "sadie"],
> "T"=>["tyler"]}

Quite true !
Thanks for the reminder.

Jesus.