CODEWITHSUNDEEP
cbinarychar
Sayam Qazi
Sayam Qazi

Reputation: 193

Binary operation in C

I have two characters 

char c1='A', c2 = 'B';

since 8-bit binary of A is 01000001 and binary of B is 01000010. I want the left-most bit of B to be put into the right-Most bit of A so that c1 becomes 01000000. I am doing this by calculating binaries A and B and then geting new binary and then doing described process and then assigning the new binary to c1. My question is whether there is there any efficient way to do this?

Upvotes: 0

Views: 175

Answers (2)

Andrew Luo
Andrew Luo

Reputation: 927

you want this:

c1 = (c1 & 0xfe) | (c2 >> 7);

Upvotes: -1

Barmar
Barmar

Reputation: 781706

The leftmost bit of c2 is:

c2 & 0x80

To move this into the rightmost bit, you use a right-shift:

(c2 & 0x80) >> 7

To combine this with c1, you first have to clear out the rightmost bit of c1:

(c1 & 0xfe)

Then you combine them with |:

c1 = (c1 & 0xfe) | ((c2 & 0x80) >> 7);

You should also change your declarations to unsigned char to avoid problems with the sign bit. It's generally best to use only unsigned variables when using bitwise operations.

Upvotes: 3

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