Kolya17 Kolya17 wrote:
> Hi!
>
> I have a two-dimensional array Farr.
>
> Farr.each{ |i| print i}
>
> output:
> ["200912-829", 9]
> ["200912-893", 3]
> ["200912-893", 5]
> ["200912-829", 1]
> ["200911-818", 6]
> ["200911-893", 1]
> ["200911-827", 2]
>
> I'm trying to get another two-dimensional array, which would be the
> grouping of the first elements.
> In SQL it would be so:
>
> select String, sum(Number)
> from Farr
> group by String
>
> and the resulting array would:
> ["200912-829", 10]
> ["200912-893", 8]
> ["200911-818", 6]
> ["200911-893", 1]
> ["200911-827", 2]
>
> Help please.
> I apologize for spelling, English is not my native.
>   
Hi,
I guess sort_by from the Enumerable Module fits your needs:
http://www.ruby-doc.org/core/classes/Enumerable.html#M003120

regards
ralf