From: Gabriel Dragffy Date: 2007-08-21T00:58:09+09:00 Subject: Re: Detecting duplicates in an array, anything in the standard library ? On 20 Aug 2007, at 14:50, Robert Klemme wrote: >> >> require 'set' >> >> new_ary = ary.to_set.to_a #set strips dups. > > It does, but as far as I can see OP wanted exactly the duplicates > back. > > Cheers > > robert > I'm a n00b, sorry if I'm poking nose in. Couldn't the op do something using &, like so: [1,2,3] & [2,3,4] == [2,3] ? Regards Gabe