Using Singleton Methods
class Creature def initialize( aSpeech ) @speech = aSpeech # from ww w.j a va 2s . com end def talk puts( @speech ) end end mySelf = Creature.new( "growl" ) def mySelf.howl if FULLMOON then puts( "How-oo-oo-oo-oo!" ) else talk end end cat = Creature.new( "miaow" ) dog = Creature.new( "woof" )
Here, even though mySelf.howl method has been declared outside the Creature class, it can call the instance method talk.
That's because the howl method now lives "inside" the mySelf object so has the same scope within that object as the talk method.
It does not, however, live inside any of the mySelf's fellow creatures.
The howl method belongs to him and him alone.