Swapping the nibbles in a char element

Question

What are nibbles in a char element?

How do we swap them?

Can anyone explain the swapping of the nibbles with an example:

The proposed duplicate question is a little erratic; it has answers for 16-bit and 32-bit nibble swapping — and a link to the [Bit Twiddling Hacks](http://graphics.stanford.edu/~seander/bithacks.html) which is a valuable resource. I'm not sure whether it qualifies as 'exact duplicate', though it is certainly closely related. — Jonathan Leffler, Apr 13 '13 at 06:17

score 8 · Accepted Answer · answered Apr 13 '13 at 06:07

8

The nibbles (or nybbles, by analogy with byte vs bite) are 4-bit chunks of a char.

You can swap them with:

c = ((c & 0x0F) << 4) | ((c & 0xF0) >> 4);

answered Apr 13 '13 at 06:07

Jonathan Leffler

score 2 · Answer 2 · edited Apr 14 '13 at 02:15

2

int x =  0xab; // 1010 1011 

int x1 = ( x & 0xF0) ; // 1010 0000
int x2 = ( x & 0x0F) ; // 0000 1011

x = ( x2 << 4 | x1 >> 4 ) ; // 1011 1010

edited Apr 14 '13 at 02:15

Jonathan Leffler

answered Apr 13 '13 at 07:31

user2247801

Santhosh Pai · Answer 3 · 2013-04-13T06:32:10.330

1

char temp1,temp2,z;// your o/p
temp1=((x & 0x0f)<<4);//x  be your input
temp2=((x & 0xf0)>>4);
z=temp1|temp2;

edited Apr 13 '13 at 06:32

answered Apr 13 '13 at 06:18

Santhosh Pai

3 Answers3