■ ASCII characters occupy the low order 8 bits of 16-bit Unicode:
0 – 9 start at hex 30, through hex 39
A – O start at hex 41, through hex 4F
P – Z start at hex 50, through hex 5A
a – o start at hex 61, through hex 6F
p- z start at hex 70, through hex 7a
a space or blank is hex 20
a period is hex 2E and a comma is hex 2C
■ System.out.print prints a
question mark ( ? ) for any unrecognizable Unicode characters.