decimalToHex.cr

def to_hex(decimal)
  decimal_remainder = decimal % 16
  hexchars = "0123456789ABCDEF"
  div = decimal / 16
  if div == 0
    hexchars[decimal_remainder].to_s
  else
    to_hex(div) + hexchars[decimal_remainder].to_s
  end
end

partial_jpeg_bytes = [255, 216, 255, 224, 0, 16, 74, 70, 73, 70]
partial_jpeg_bytes.each do |b|
  puts to_hex(b)
end