From: Logan Capaldo <logancapaldo@...>
Date: 2006-03-04T02:44:20+09:00
Subject: Re: Array comparison returning nil


On Mar 3, 2006, at 8:37 AM, Julian Gall wrote:

> I am comparing two arrays with:
>
> original_item_ids.sort <=> new_item_ids.sort
>
> However, this returns nil, which seems to be against the documentation
> which says the result will be -1, 0 or 1. Both arrays contain the same
> values, alhough in a different order, hence the sort.
>
> Does anyone know of any circumstance that would cause this?
>
> Thanks,
>
> Julian
>
> -- 
> Posted via http://www.ruby-forum.com/.
>

<=> will return nil when a comparision makes no sense

eg:

irb(main):013:0> a = "a"
=> "a"
irb(main):014:0> b = 2
=> 2
irb(main):015:0> a <=> b
=> nil