From: Dave Thomas <dave@...>
Date: 2008-02-12T01:51:15+09:00
Subject: Re: Array#sort unexpected behaviour


On Feb 11, 2008, at 10:47 AM, daniel åkerud wrote:

> irb(main):044:0> a=[[1, "abc"],[3, "def"],[2, "efg"]]
> => [[1, "abc"], [3, "def"], [2, "efg"]]
> irb(main):045:0> a.sort { |a, b| a[0] <=> b[0] }
> => [[1, "abc"], [2, "efg"], [3, "def"]]
> irb(main):046:0> a
> => [1, "abc"]
>
> A new sorted array is correctly returned, but "a" itself is not left  
> intact.
> It seems to have something to do with me using an array-of-arrays.


Your block parameter is also called 'a'.

In Ruby 1.9, this isn't an issue, but in 1.8, the variable is the same  
as the block parameter.


Dave