From: Michael Guterl <mguterl@...>
Date: 2008-09-14T20:21:37+09:00
Subject: Re: getting an array of unique objects of a class i wrote

On Sun, Sep 14, 2008 at 7:08 AM, Adam Akhtar <adamtemporary@gmail.com> wrote:
> Hi Ive done some searching on this but couldnt find an answer that was
> either totally appropriate or one that i could understand ;> (some
> advanced stuff going on).
>
> So if i have a class with two variables (strings) like this
>
> class thing
> attr_accessor :name :job
> end
>
> and i want to ensure that if i have an array of these objects there will
> be no duplicates. A duplicate would be where both the name and job are
> the same in both objects.
>
> I tried using uniq! but it didnt work. Not sure why (can someone explain
> that).
>
> Ive heard of set, could that be used in this case to prevent duplicates
> being added?

You need to implement Thing#eql? and Thing#hash in order for a
Array#uniq, Set, or Hash to function as you expect.