From: "David A. Black" <dblack@...>
Date: 2008-08-29T09:59:01+09:00
Subject: Re: Class ===

Hi --

On Fri, 29 Aug 2008, Patrick Doyle wrote:

> and I would also like to know why
>
> x = Array.new()
> => []
> x === Array
> => false

Because the instance method Array#=== is not defined as a test of
class membership. I believe it's the default ===, which is the same as
==.

> I've just got to teach to use:
>
> case x
> when Array
>   ...
> end
>
> instead of
> if x === Array
>   ...
> end
>
> ...the few times I want to do something only when x is an array.

You can do:

   if Array === x

=== is the case equality operator, so this:

   case obj
   when x

is like this:

   if x === obj


David

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