ruby的include与extend
ruby提供了强大的继承机制,有关继承的方法很多。最简单就是“
module Foo def foo puts 'heyyyyoooo!' end end class Bar include Foo end Bar.new.foo # heyyyyoooo! Bar.foo # NoMethodError: undefined method ‘foo’ for Bar:Class class Baz extend Foo end Baz.foo # heyyyyoooo! Baz.new.foo # NoMethodError: undefined method ‘foo’ for #0x1e708>