# define a class

class Box

   # constructor method

   def initialize(w,h)

      @width, @height = w, h

   end

​

   # instance method by default it is public

   def getArea

      getWidth() * getHeight

   end

​

   # define private accessor methods

   def getWidth

      @width

   end

   def getHeight

      @height

   end

   # make them private

   private :getWidth, :getHeight

​

   # instance method to print area

   def printArea

      @area = getWidth() * getHeight

      puts "Big box area is : #@area"

   end

   # make it protected

   protected :printArea

end

​

# create an object

box = Box.new(10, 20)

​

# call instance methods

a = box.getArea()

puts "Area of the box is : #{a}"

​

# try to call protected or methods

box.printArea()