In general you are correct, redefinition in Ruby can be abused, but it isn't so easy to abuse 'nil' in Ruby as it is to abuse 'undefined' in Javascript. In Rub

In general you are correct, redefinition in Ruby can be abused, but it isn't so easy to abuse 'nil' in Ruby as it is to abuse 'undefined' in Javascript. In Ruby, nil, is a keyword so you can't assign to it nor can you use it as a method parameter.