From: David Garamond <lists@...6.isreserved.com>
Date: 2004-02-01T21:15:50+09:00
Subject: Re: check whether a class is defined, listing all classes

Robert Klemme wrote:
>>  p class_defined?("Test::Unit::TestCase") # false
>>  require 'test/unit/testcase'
>>  p class_defined?("Test::Unit::TestCase") # true
>>
>>Is there an easier way?
> 
> irb(main):009:0> defined? Test::Unit::TestCase
> => nil
> irb(main):010:0> require 'test/unit/testcase'
> => true
> irb(main):011:0> defined? Test::Unit::TestCase
> => "constant"

But what if the class name to be checked is a string? 
("Test::Unit::TestCase")? Btw, is "defined?" a method (of what class?)? 
A statement?

>>A bonus question, how do I list all the defined classes in their fully
>>qualified name? Example output:
> 
> ObjectSpace.each_object( Class ){|cl| p cl}
> ObjectSpace.each_object( Class ){|cl| p cl.name}

Ah, Class#name... Thanks, I'm so glad it's straightforward & easy.

-- 
dave