From: "David A. Black" <dblack@...>
Date: 2009-09-27T00:54:13+09:00
Subject: Re: How to remove duplicate elements in a 2D array

Hi --

On Sun, 27 Sep 2009, Rick DeNatale wrote:

> I like David Black's alternative suggestion:
>
>  result = arr.inject({}){|x,y| x[y[0]]=y; x}.values
>
> Note that neither of these preserve the ordering of the rows retained
> from the original array in Ruby 1.8.x, but if you're happy I guess
> that's not a requirement.

And in 1.9, you can do this:

   arr.map.with_object({}) {|e,h| h[e[0]] = e }.values

which gets rid of the need to force the accumulator to be the hash
every time through.


David

-- 
David A. Black, Director
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Ruby/Rails training, consulting, mentoring, code review
Book: The Well-Grounded Rubyist (http://www.manning.com/black2)