ruby - Initializing instance variables inside << self blocks -

specifically, why following code output nil instead of 1?

class foo   class << self     @bar = 1     def bar       @bar     end   end end p foo.bar 

in << self block, self instance of #<class:foo>.

class foo   puts "self in foo declaration is: #{self} #{self.class} #{self.object_id}"   class << self      @bar = 1     puts "self in foo.self declaration is: #{self} #{self.class} #{self.object_id}"     def bar       puts "self in class method #{self} #{self.class} #{self.object_id}"       @bar     end   end end p foo.bar 

this code outputs:

self in foo declaration is: foo class 69910818825400 self in foo.self declaration is: #<class:foo> class 69910818825380 self in class method foo class 69910818825400 

so slight modification code, works expected, is:

class foo @bar = 1 class << self def bar @bar end end end p foo.bar