From: Robert Klemme <bob.news@...>
Date: 2005-10-13T18:46:54+09:00
Subject: Re: array1 + array2 newb question

Kroeger, Simon (ext) wrote:
>> From: Robert Klemme [mailto:bob.news@gmx.net]
>> Since there hasn't been an #inject solution so far... :-)
>
> hmm, is the gateway broken again?
>
> a1.inject([]){|s, x| s + a2.map {|y| [x, y]}}
>
> (posted 1 hour ago)

No, it's here.  Can't tell though whether I just overlooked it or whether
the posting arrived here after I wrote mine.

And note that your version has the disadvantage that you copy s all the
time.  Using concat is more efficient.  Even if you use that there's an
intermediate array per x value that is dropped again.  That's why my
solution just appends two element arrays to the collecting array. :-)

Kind regards

    robert