>>>>> "r" == ralf  <stark.dreamdetective / googlemail.com> writes:

r> hash = Hash.new("")
r> => {}
r> hash["a"] << "b"

 When you write this :
  1) ruby return the default value for the hash ('a' don't exist as a key)
  2) concatenate "b" to this default value (see String#<<)

 Finally you have modified the default value for the hash, and you can see
 this here :

r> hash["alskj"]
r> => "b"

  ruby now give the new default value



Guy Decoux