From: James Edward Gray II <james@...>
Date: 2006-03-07T06:54:29+09:00
Subject: Re: What is the best way to iterate through two containers of the same length?

On Mar 6, 2006, at 3:48 PM, Mark Watson wrote:

> If I have two containers c1 and c2 of the same length, what is the
> proper "Ruby way" to do this:
>
> c1.length.times {|i|
>   # access c1[i], c2[i]
> }
>
> I like that Ruby container classes provide their own iterators, but
> what I would like to have is something like:
>
> (c1,c2).each {|x1,x2| .... }

You are looking for Enumerable#zip:

 >> letters = %w{A B C}
=> ["A", "B", "C"]
 >> numbers = [1, 2, 3]
=> [1, 2, 3]
 >> letters.zip(numbers) do |letter, number|
?>   puts "#{letter}#{number}"
 >> end
A1
B2
C3
=> nil

You can also use the standard generator library to turn Ruby's  
internal iterators into external iterators (like Java's iterators) if  
needed.

Hope that helps.

James Edward Gray II