Modify Self, Ruby

Question

module Pigged
  String.class_eval do
    def pig
      newstring = self + self[0]; newstring[0] = ""; newstring += "ay"
      return newstring
    end
  end
end

is the relevant code. What I want to do is make a method, pig!, that modifies the original string. How do I do that, without modifying self, because that is not allowed...?

Answer 1

I've condensed your code a little and added the pig! method :

module Pigged
  String.class_eval do
    def pig
      self[1..-1] + self[0] + 'ay'
    end
    def pig!
      self.replace(pig) #self.replace(self[1..-1] + self[0] + 'ay')
    end
  end
end

Answer 2

You shouldn't modify self.

Use replace or a custom method.

Read 'Writing method "change!" for String' for more information.