From: Li Chen <chen_li3@...>
Date: 2009-09-26T23:56:39+09:00
Subject: Re: How to  remove duplicate elements in a 2D array

Thairuby ->a, b {a + b} wrote:
> The method ".map(&:flatten)" is use to converse hash back to array.


Thanks.

But I still have some doubts about this line:

 result = arr.inject({}){|x,y| x[y[0]]=y[1..-1];
               x
              }.map(&:flatten)


1) When I look at #inject method, I notice it only takes either no 
augument or
an augument with initial value. But in your code it takes a hash. It is 
kind of new/strange to me.

2) Why do you  write an x alone after this line  x[y[0]]=y[1..-1]; ?

3) #map(&:flatten) doesn't work in my Ruby version(1.8.6). Which version 
are you using? But I make some changes and it works.

result = arr.inject( {  }  ){|x,y| x[y[0]]=y[1..-1]; x}.to_a
r=result.collect { |row| row.flatten}

Li
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