How to use bitwise operators to isolate bits from unsigned ints in C?

Question

this seems to be working well for me except this one time. I'm trying to get the first 10 bits of this number

unsigned char c= 17512807u<<22>>22;

I expect this to be 359 or 0101100111 but I'm getting 103 or 0001100111. Is there a reason that this is happening?

Answer 1

The result you are getting is correct due to the truncation to 8-bit unsigned char value (when assigning to c ).

If you need a value that is 10-bits wide you should use a different datatype, like uint16_t or an unsigned int .

Reference to C++ integer datatypes