From: E S <eero.saynatkari@...>
Date: 2005-02-05T07:37:23+09:00
Subject: Re: iteration the ruby way

> L�hett�j�: Navindra Umanee <navindra@cs.mcgill.ca>
> Aihe: Re: iteration the ruby way
> 
> John Wilger <johnwilger@gmail.com> wrote:
> > > I have a question about The Ruby Way.  Pickaxe gives the following
> > > example for using iterators in Ruby:
> > > 
> > > a = [ "a", "b", "c" ]
> > > a.each {|x| print x, " -- " }
> > > 
> > > This outputs:
> > > 
> > > a -- b -- c --
> > > 
> > > But what if I want to print "a -- b -- c"?  What's the proper Ruby way
> > > of doing that?
> > 
> > a = ["a","b","c"]
> > puts a.join(' - ')
> 
> I guess I over-simplified.  I really want to do computations based on
> each element and compute my output.  However, it's slightly different
> for the last element.  I would like to detect the last element in the
> iteration.
> 
> For example:
> 
>      bottom_items.each{ |item|
>         do_something_with(item[0], item[1], item[2])
> 	if_not_last_item_do_this    
>      }

Since you're not doing the same thing on all elements, these should
be conceptually correct. 

  ary = ary[0..-1].each {|el| do_something el }
  do_something_else!(ary.last)

  ary.each_index {|i| do_smth(ary[i]) unless i == ary.size - 1} 

> Thanks,
> Navin.

E