From: ES <ruby-ml@...>
Date: 2005-10-13T13:15:03+09:00
Subject: Re: array1 + array2 newb question

Mike Schramm wrote:
> Hey all,
> 
> I'm a ruby newbie, so this will be obvious, but I can't figure it out.
> 
> I'm trying to create a map grid from arrayed names of streets.  I  want 
> to go from [1,2,3] and [a,b,c] to [[1,a], [2,a], [3,a],  [1,b],... [3,c]].
> 
> so far the closest I have gotten is
> 
> a1.collect!{|x| [x, a2.collect!{|y| y}]}
> 
> which returns-- well you can try it if you like, but it's not right.   
> Instead of just returning one value of a2 at a time, it returns the  
> whole thing every time.  I'm guessing I need to somehow cycle through  
> each element of a2 (ie a2[0], a2[1], a2[2]), but I can't figure it out.
> 
> You guys will probably eat this up.  What am I so obviously doing wrong?

You are close but there is no cookie for you! :) You are just constructing
the Array at the wrong place.

   [1,2,3].map {|i| [:a, :b, :c].map {|l| [i, l]}}

(Substitute #collect for #map if you wish.) Does that make sense?

> Mike

E