01.rb

class Basket
  def initialize
    # use private setter to initialize variable
    set_contents(:empty)
  end

  def fill_basket
    set_contents(:fruit)
  end

  private

  def set_contents(contents)
    @contents = contents
  end
end

02.rb

class Basket
  def initialize
    # initialize variable directly
    @contents = :empty
  end

  def fill_basket
    set_contents(:fruit)
  end

  private

  def set_contents(contents)
    @contents = contents
  end
end

03.rb

# don't bother with setter for simple variables
class Basket
  def initialize
    @contents = :empty
  end

  def fill_basket
    @contents = :fruit
  end
end

class Basket
  def initialize
    contents = :empty
  end

  def fill_basket
    contents = :fruit
  end

  private
  attr_accessor :contents
end