exploring-rubys-object-model.rb

irb(main):001:0> Class.class
=> Class
irb(main):002:0> Class.superclass
=> Module
irb(main):003:0> Module.superclass
=> Object
irb(main):004:0> Object.superclass
=> BasicObject
irb(main):005:0> BasicObject.superclass
=> nil
irb(main):006:0> nil.class
=> NilClass
irb(main):007:0> NilClass.superclass
=> Object
irb(main):008:0> # halp I'm trapped

jake ~ » irb                                                         [14:06:04]
irb(main):001:0> a
NameError: undefined local variable or method `a' for main:Object
    from (irb):1
    from /Users/jake/.rubies/ruby-2.1.2/bin/irb:11:in `<main>'
irb(main):002:0> b
NameError: undefined local variable or method `b' for main:Object
    from (irb):2
    from /Users/jake/.rubies/ruby-2.1.2/bin/irb:11:in `<main>'
irb(main):003:0> a = b
NameError: undefined local variable or method `b' for main:Object
    from (irb):3
    from /Users/jake/.rubies/ruby-2.1.2/bin/irb:11:in `<main>'
irb(main):004:0> a = a
=> nil
irb(main):005:0>