From: "David A. Black" <dblack@...>
Date: 2009-09-27T01:36:21+09:00
Subject: Re: How to remove duplicate elements in a 2D array

Hi --

On Sun, 27 Sep 2009, pharrington wrote:

>> r.map {|x| x.first if x.first == e.first}.compact.size == 0
>
> I'm an idiot, Ruby likes to call this pile of silliness "detect":
>
> arry.reverse.inject([]) {|r, e| r.unshift(e) unless r.detect {|x|
> x.first == e.first}; r}

Couldn't resist throwing in another 1.9-esque version:

   arr.group_by(&:first).map(&:last).map(&:last)

:-) Of course mapping to [-1][-1] would work too (and probably more
efficiently).


David

-- 
David A. Black, Director
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Book: The Well-Grounded Rubyist (http://www.manning.com/black2)