Why use hex?

Question

Hey! I was looking at this code at http://www.gnu.org/software/m68hc11/examples/primes_8c-source.html

I noticed that in some situations they used hex numbers, like i

Answer 1

I find it maddening that the C family of languages have always supported octal and hex but not binary. I have long wished that they would add direct support for binary:

int mask = 0b00001111;

Many years/jobs ago, while working on a project that involved an enormous amount of bit-level math, I got fed up and generated a header file that contained defined constants for all possible binary values up to 8 bits:

#define b0        (0x00)
#define b1        (0x01)
#define b00       (0x00)
#define b01       (0x01)
#define b10       (0x02)
#define b11       (0x03)
#define b000      (0x00)
#define b001      (0x01)
...
#define b11111110 (0xFE)
#define b11111111 (0xFF)

It has occasionally made certain bit-level code more readable.