From: William James <w_a_x_man@...>
Date: 2006-12-21T08:05:06+09:00
Subject: Re: tricky sort for happy visitors of Paris

Jos Backus wrote:
> More generally:
>
> lizzy:~% irb
> irb(main):001:0> arrondissements = ["Paris 1", "Paris 2","Paris 4", "Paris 3", "Lyon 2", "Lyon 1"]
> => ["Paris 1", "Paris 2", "Paris 4", "Paris 3", "Lyon 2", "Lyon 1"]
> irb(main):002:0> sorted_array = arrondissements.sort_by {|e| [e.split(" ")]}
> => ["Lyon 1", "Lyon 2", "Paris 1", "Paris 2", "Paris 3", "Paris 4"]
> irb(main):003:0> %                                                              lizzy:~%
>
> --
> Jos Backus
> jos at catnook.com

Won't work for

arrondissements = "Paris 1", "Paris 2","Paris 12", "Paris 3",
  "Lyon 2", "Lyon 1"

For the 2nd field, you need a numeric comparison.

p arrondissements.sort_by {|e|  e.split.inject{|a,b| [a,b.to_i] } }