# Bit and Byte problem

Discussion in 'C Programming' started by cjw, Oct 17, 2003.

1. ### cjwGuest

I need to read an 'unsigned char' array and save it as a bit array
(values are only 0s or 1s). When processing, have to do math
operations such as summing up the values etc. Pl let me know an
efficient way of doing this.
cjw

cjw, Oct 17, 2003

2. ### Tristan MillerGuest

Greetings.

In article <>, cjw wrote:
> I need to read an 'unsigned char' array and save it as a bit array
> (values are only 0s or 1s). When processing, have to do math
> operations such as summing up the values etc. Pl let me know an
> efficient way of doing this.

Given your e-mail address and the nature of the query, I presume this is a
homework problem. Fortunately, it's not too hard to solve if you read up
on C's bit-shifting operators (<< and >>). Once you've done so, try
writing the program, and if you need help, send another post with your code
and a description of the problem.

Regards,
Tristan

--
_
_V.-o Tristan Miller [en,(fr,de,ia)] >< Space is limited
/ |`-' -=-=-=-=-=-=-=-=-=-=-=-=-=-=-= <> In a haiku, so it's hard
(7_\\ http://www.nothingisreal.com/ >< To finish what you

Tristan Miller, Oct 17, 2003

3. ### Ravi UdayGuest

(cjw) wrote in message news:<>...
> I need to read an 'unsigned char' array and save it as a bit array
> (values are only 0s or 1s). When processing, have to do math
> operations such as summing up the values etc. Pl let me know an
> efficient way of doing this.
> cjw

What you mean by bit array !! Is it 8 bits in 1 byte you call as array
??
Well, an array is composed of bytes of type the array points to and
each
byte is composed of 8 bits. Bit values help to represent the value in
that byte to read and process them.
Define your problem or post snippet of your compilable code in order

- Ravi

Ravi Uday, Oct 17, 2003
4. ### Irrwahn GrausewitzGuest

(Ravi Uday) wrote:

> (cjw) wrote in message news:<>...
>> I need to read an 'unsigned char' array and save it as a bit array
>> (values are only 0s or 1s). When processing, have to do math
>> operations such as summing up the values etc. Pl let me know an
>> efficient way of doing this.
>> cjw

>
>What you mean by bit array !! Is it 8 bits in 1 byte you call as array
>??
>Well, an array is composed of bytes of type the array points to and

No.
An array is a contiguous set of objects of a particular type.
An array object doesn't point to anything, though it decays into a
pointer to its first element in value contexts.

>each
>byte is composed of 8 bits.

No.
A byte is /at least/ eight bits in width.

>Bit values help to represent the value in
>that byte to read and process them.

Value bits represent the value of an object. Padding bits don't.

>Define your problem or post snippet of your compilable code in order

Seconded.
--
Irrwahn
()

Irrwahn Grausewitz, Oct 17, 2003
5. ### Ravi UdayGuest

Irrwahn Grausewitz <> wrote in message news:<>...
> (Ravi Uday) wrote:
>
> > (cjw) wrote in message news:<>...
> >> I need to read an 'unsigned char' array and save it as a bit array
> >> (values are only 0s or 1s). When processing, have to do math
> >> operations such as summing up the values etc. Pl let me know an
> >> efficient way of doing this.
> >> cjw

> >
> >What you mean by bit array !! Is it 8 bits in 1 byte you call as array
> >??
> >Well, an array is composed of bytes of type the array points to and

>
> No.
> An array is a contiguous set of objects of a particular type.
> An array object doesn't point to anything, though it decays into a
> pointer to its first element in value contexts.
>

Really .. Clever !

> >each
> >byte is composed of 8 bits.

>
> No.
> A byte is /at least/ eight bits in width.
>
> >Bit values help to represent the value in
> >that byte to read and process them.

>
> Value bits represent the value of an **object** oh. Padding bits don't. -> Yes i forgot about that
>
> >Define your problem or post snippet of your compilable code in order