CODEWITHSUNDEEP
cvariable-assignmentbithamming-code
Nasser Kessas
Nasser Kessas

Reputation: 361

Is there a way to set the value of an variable by the bits to comprise it?

I am trying to make a hamming code decoder and encoder in C and I cannot find a way to set the bits of a variable individually.

For example, I am trying to somehow do the following:

#include "stdio.h"

int main () {
    short block = 0010101110001110; // variable to contain the bits to decode
}

Clearly this will not work but I am wondering if there is a way to do this or will I have to define it as the actual number this represents?

Upvotes: 0

Views: 71

Answers (2)

chux
chux

Reputation: 153547

The next version of C C2x is expected to support binary constants like 0b0010101110001110.

For now, consider hexadecimal constants or perhaps a macro.

Tip: typically such code works best with unsigned types.

#define BIN16U(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) ( \
   ((unsigned)(a)<<15) | ((b)<<14) | ((c)<<13) | ((d)<<12) | \
             ((e)<<11) | ((f)<<10) | ((g)<< 9) | ((h)<< 8) | \
             ((i)<< 7) | ((j)<< 6) | ((k)<< 5) | ((l)<< 4) | \
             ((m)<< 3) | ((n)<< 2) | ((o)<< 1) | ((p)<< 0))

unsigned short block = BIN16U(0,0,1,0, 1,0,1,1, 1,0,0,0, 1,1,1,0);

Upvotes: 1

dbush
dbush

Reputation: 224082

You can use hexadecimal representation, where each digit represents exactly 4 bits.

unsigned short block = 0x2b8e;

Upvotes: 1

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