Grabbing n bits from a byte

Question

I\'m having a little trouble grabbing n bits from a byte.

I have an unsigned integer. Let\'s say our number in hex is 0x2A, which is 42 in decimal. In binary it looks li

Answer 1

int x = (number >> 3) & 0x1f;

will give you an integer where the last 5 bits are the 8-4 bits of number and zeros in the other bits.

Similarly,

int y = number & 0x7;

will give you an integer with the last 3 bits set the last 3 bits of number and the zeros in the rest.