From: Joel VanderWerf <vjoel@...>
Date: 2005-02-13T06:50:15+09:00
Subject: Re: const_defined? and inheritance

Kevin Howe wrote:
>>> 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

An alternative:

p defined?(B::FOO)      # ==> "constant"

But this will include more than just the constants defined by A and B:

p defined?(B::Object)   # ==> "constant"