From: Rick DeNatale <rick.denatale@...>
Date: 2007-06-21T04:20:48+09:00
Subject: Re: if == any item in an array

On 6/20/07, 12 34 <rubyforum@web.knobby.ws> wrote:
> I'd like to write something like
>
> PhotoEndings = %w[JPG,MRW,JPE]
> MovieEndings = %w[AVI]
> case ext # determined from the photo file name
> when PhotoEndings
> <do something whenever ext is the same as any of the photo endings. >
> when MovieEndings
> <do something else>
> else
> end
>
> I don't have to use case, any conditional will do.
>
> Thanks. I hope I have explained this. I have no idea what to search for.
> I did try some, but I'm a newbie and don't understand the more advanced
> syntax.
>
> I tried
> when PhotoEndings.any
> and
> when PhotoEndings.or
>

case
when PhotoEndings.include?(ext)
....
when MovieEndings.include?(ext)
...
end

The form
  case x
  when y
    #do something
  when z
     #do something else
  end
...

is actually equivalent to:

   if y === x
   then
      #do something
   elsif z === x
      # do something else
   end

and

   case  #no value
   when y
       # do something
   when z
       # do something else
    end

   if y
   then
      #do something
   elsif z
      # do something else
   end


-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/