instance method

#!/usr/bin/ruby -w

# define a class
class Box
   # constructor method
   def initialize(w,h)
      @width, @height = w, h
   end
   # instance method
   def getArea
      @width * @height
   end
end

# create an object
box = Box.new(10, 20)

# call instance methods
a = box.getArea()
puts "Area of the box is : #{a}"