`respond_to?` vs. `respond_to_missing?`
Without respond_to_missing? defined, trying to get the method via method will fail:
class Foo def method_missing name, *args p args end def respond_to? name, include_private = false true endendf = Foo.newf.bar #=> []f.respond_to? :bar #=> truef.method :bar # NameError: undefined method `bar' for class `Foo'class Foo def respond_to? *args; super; end # “Reverting” previous redefinition def respond_to_missing? *args true endendf.method :bar #=> #<Method: Foo#bar>Marc-André (a Ruby core committer) has a good blog post on respond_to_missing?.
It's a good practice to create respond_to_missing? if you are overriding method_missing. That way, the class will tell you the method you are calling exists, even though it's not explicitly declared.
respond_to? should probably not be overriden :)