gistfile1.txt

#!/usr/bin/ruby

class Foo
  attr_accessor :name, :age
  
  def initialize
    @options = {:name => "Tim", :age => 28}
  end
  
  def work(h)
    @options.merge!(h).each do |k,v|
      self.instance_variable_set(:"@#{k}",v)
    end
  end
end

f = Foo.new

f.work(:age => 30)

puts f.age