From: Joel VanderWerf <vjoel@...>
Date: 2007-11-05T08:19:20+09:00
Subject: Re: Check if MyClass extends OtherClass?

Joshua Muheim wrote:
> How can I check if MyClass extends OtherClass? When I have an instance I
> can call my_class_instance.kind_of?(OtherClass), but what can I call
> when only having the class name?

Use the #< and #<= methods of classes (and modules):

class OtherClass
end

class MyClass < OtherClass
end

classes = [MyClass, OtherClass]
classes.each do |c1|
   classes.each do |c2|
     puts "#{c1} < #{c2}" if c1 < c2
     puts "#{c1} <= #{c2}" if c1 <= c2
   end
end

__END__

Output:

MyClass <= MyClass
MyClass < OtherClass
MyClass <= OtherClass
OtherClass <= OtherClass

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407