From: Jeff Peng <jeffpeng@...>
Date: 2010-01-06T19:17:40+09:00
Subject: Re: group in the array

Kolya17 Kolya17:

> 
> I'm trying to get another two-dimensional array, which would be the
> grouping of the first elements.
> In SQL it would be so:
> 


Hi,

You could use a hash for translating that.

x= [["200912-829", 9],["200912-893", 3],["200912-893", 5],["200912-829", 
1],["200911-818", 6],["200911-893", 1],["200911-827", 2]]

hash = Hash.new(0)
x.each do |c| hash[c[0]] += c[1] end

new = hash.to_a
p new