c get nth byte of integer

Question

I know you can get the first byte by using

int x = number & ((1<<8)-1); 

or

int x = number & 0xFF; 

But I don't know how to get the nth byte of an integer. For example, 1234 is 00000000 00000000 00000100 11010010 as 32bit integer How can I get all of those bytes? first one would be 210, second would be 4 and the last two would be 0.

Answer 1

int x = (number >> (8*n)) & 0xff; 

where n is 0 for the first byte, 1 for the second byte, etc.

Answer 2

For the (n+1)th byte in whatever order they appear in memory (which is also least- to most- significant on little-endian machines like x86):

int x = ((unsigned char *)(&number))[n]; 

For the (n+1)th byte from least to most significant on big-endian machines:

int x = ((unsigned char *)(&number))[sizeof(int) - 1 - n]; 

For the (n+1)th byte from least to most significant (any endian):

int x = ((unsigned int)number >> (n << 3)) & 0xff; 

Of course, these all assume that n < sizeof(int), and that number is an int.