Re: Hexadecimal and bitwise operations

{ edits: double-spacing removed manually. -mod }

<Hakusa@[EMAIL PROTECTED]
> wrote in message
news:a3532269-02f3-4f97-afa9-cf9a9303f9bd@[EMAIL PROTECTED]
 Maybe this is just my lack of experience with working with hex, but...
:
: I was asked to produce an M-tree class using unsigned ints in hex to
: traverse through and find nodes. The thing I'm having trouble working
: out is, I was given (on paper) 25E1 & 0010 = 00E0, but when I tried it
: on my computer, I found C++ converting it all to binary and producing
: 0x4 & 0x3 = 100 & 011 = 0.
Indeed, the operation happens bit-wise.

: Obviously, that's not helpful. How can I take my hex numbers and do
: the & operation? Or maybe my question is wrong--how can I access the
: n'th digit?
You access the n'th digit by using a mask where all bits corresponding
with the hex digit are set.
Assuming that you expect  a=0x25E1  and  b=0x0010  to result in
r=0x00E0,
one approach would be to write:
   r = a & (b*0xF)
If you want to extract the digit as a value in 0..0xF:
   r = (a/b)&0xF;   // -> 0xE;

In some cases, using the bit-****ft operators << and >> may be
useful too.

: NOTE: This thread was created after about an hour or more of research.
: Simply pointing me in the right direction would be appreciated.

I hope this is enough to inspire you... -Ivan
-- 
http://ivan.vecerina.com/contact/?subject=NG_POST
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Brainbench MVP for C++ <> http://www.brainbench.com


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