white_board.oop

class Whiteboard

attr_accessor :contents
  def initialize(contents = [])
    @contents = contents
  end

  def dry_marker_eraser
    @contents = []
  end
end

class DryEraseMarker
  attr_reader :color, :capacity
  def initialize(color)
    @color = color
    @capacity = 100
  end

  def ink_remaining?
    !@capacity.nil?
  end
    

  INK_USE_PER_CHARACTER = 0.01
  def write(contents, whiteboard)

    @capacity = @capacity - (INK_USE_PER_CHARACTER * contents.length)
    whiteboard.contents << contents
  end
end

whiteb = Whiteboard.new
black_marker = DryEraseMarker.new("black")
black_marker.write("hello launch", whiteb)
require "pry"
binding.pry