From: Gary Wright <gwtmp01@...>
Date: 2009-03-19T00:38:20+09:00
Subject: Re: Complex sort of matrix possible, e.g. like Excel?


On Mar 18, 2009, at 6:16 AM, Robert Klemme wrote:
> You can as well do
>
> arr.sort_by {|a,b| [a[0]<=>b[0], b[1]<=>a[1]]}

This doesn't seem quite right to me.  Shouldn't it be:

arr.sort_by { |item| [item[0], item[1]] }

sort_by will use Array#<=> to compare the two element
array and Array#<=> simply uses <=> on each element.

Gary Wright