> I think you're asking how to make the "outside" variable (here, the
> "a" Array) a global variable. You need to prefix its name with the "$"
> character, i.e.
> 
>     class Gate
>         def update
>             @state = $a[1].state
>         end
>     end
> 
> and
> 
>     $a = Array.new
>     num.times { |i|
>         $a[i] = Gate.new
>         etc.
>     }
> 
> But of course, you really should avoid using global variables if you
> can help it.


Yes, that is very much what I'm looking for. At this stage it works.
Thank you.