How do character ranges ACTUALLY work in regex?

Question

To avoid confusion, I'm not asking how to use character ranges in regex. I'm asking how they actually work behind the scenes.

Character ranges in regex are indicated using the - (dash) character between square brackets. At first, I thought we can only range between A-Z (lowercase or uppercase) and 0-9. Just now, I found out you can also do N-P.

I thought to myself what if it actually uses ASCII character codes like if I defined [ -/], it'll be the same as 32 <= x <= 47 (32 and 47 are ASCII codes for space ' ' and forward slash '/').

Do character ranges work like this???

Answer 1

No, it's not based on ascii order, it's based on alphabetical order.

Answer 2

Take a look at https://stackoverflow.com/questions/150033/regular-expression-to-match-non-ascii-characters