From: Kevin Howe <kh@...>
Date: 2005-02-13T06:39:58+09:00
Subject: Re: const_defined? and inheritance

> >  class A
> >    FOO = 'BAR'
> >  end
> >
> >  class B < A; end
> >
> >  puts A.const_get(:FOO) # => 'BAR'
> >  puts A.const_defined?(:FOO) # => true
> >  puts B.const_get(:FOO) # => 'BAR'
> >  puts B.const_defined?(:FOO) # => false
> >

> I think they're just two different operations.  The constants a module
> can see ("get") is a superset of the constants it's defined.

If that were the case then B.const_get(:FOO) would raise an error since B
does not define FOO. Instead it inherits it from A, and returns the
inherited value of "BAR". But you are probably right in the sense that
const_defined? shows only those explicitly set in that particular class.
I'll just use constants.include?('FOO') instead.

Regards,
Kevin