ruby-processing keyCode for key_pressed

keycodes.rb

# 38up 39right 40down 37left
def key_pressed
  
  case key_code
  when 32
    puts 'space'
  when 37
    puts 'left'
  when 38
    puts 'up'
  when 39
    puts 'right'
  when 40
    puts 'down'
  end
end