require 'pp'
class Attributes
  attr_reader :string, :array, :hash
  def initialize
    @string = 'value'
    @array = [1, 2, 3, 4]
    @hash = { name: 'Carlos', age: 25 }
  end
end

instance = Attributes.new
pp 'Original atributes:'
pp '-------------------------'
pp instance.string
pp instance.array
pp instance.hash
pp '-------------------------'

# bang!!
# this should not afect the original atribute.
instance.string.gsub!(/.*/, '')
instance.array.clear
instance.hash.clear

pp 'After Hacking attributes:'
pp '-------------------------'
pp instance.string
pp instance.array
pp instance.hash
pp '-------------------------'