Unsigned and signed char types

[Sriniv]

Hello all,
Do we have unsigned and signed char types? If so, i'd like to know the
differences between the two.
And one more question. Is there any provision in C for using the
Unicode character set?
Thank you.
-- Srinivasan.

 

[Emmanuel Delahaye]

Sriniv wrote on 12/06/05 :

Do we have unsigned and signed char types?

Yes, there are 3 char= types:

char : used for strings

signed char
and
unsigned char : used for small integers (mainly in arrays).

If so, i'd like to know the
differences between the two.

For the signed/unsigned types, the difference is the range and the
behaviour on overflow. More details in your C-book.

http://publications.gbdirect.co.uk/c_book/ (C90)

And one more question. Is there any provision in C for using the
Unicode character set?

Yes, the C95 wchar_t type and related w*() functions.

--
Emmanuel
The C-FAQ: http://www.eskimo.com/~scs/C-faq/faq.html
The C-library: http://www.dinkumware.com/refxc.html

..sig under repair

 

[Ben Pfaff]

Yes, there are 3 char= types:

char : used for strings [...]

It is certainly true that `char' is the type most often used for
strings. However, the C standard doesn't restrict the definition
of "string" to `char' only:

7.1 Introduction
7.1.1 Definitions of terms
1 A string is a contiguous sequence of characters terminated by
and including the first null character.

This may or may not be useful to know outside of comp.lang.c.

 

[Lawrence Kirby]

Sriniv wrote on 12/06/05 :

Yes, there are 3 char= types:

char : used for strings

signed char
and
unsigned char : used for small integers (mainly in arrays).


For the signed/unsigned types, the difference is the range and the
behaviour on overflow. More details in your C-book.

As such they are like other signed and unsigned integer types.

http://publications.gbdirect.co.uk/c_book/ (C90)


Yes, the C95 wchar_t type and related w*() functions.

Even C89 has some wide character support. Note that as with normal
charcters the character encoding is not specified so it need not be
Unicode.

Lawrence

 

[William Ahern]

Hello all,
Do we have unsigned and signed char types? If so, i'd like to know the
differences between the two.
And one more question. Is there any provision in C for using the
Unicode character set?

FWIW, Unicode isn't simply a "character set". It's a whole set of rules and
methodologies. C in it's C99 incarnation is about as close to supporting
Unicode as it was when Unix was rewritten in C 30 years ago.

Some will mention wchar_t and the new wide character functions. But wchar_t
gives you absolutely zilch, no matter whether it's 16-bits or 32-bits or
128-bits. The char type suffices just as well, because no matter the width
of the type you _still_ have combining characters, so the whole notion of
mapping a glyph (the things you see on your screen) to a "character" is long
dead, particularly with regards to Unicode.

So, depending on your disposition C either has no support for Unicode, or it
supports it just fine. IOW, you can use libraries like IBM's ICU to deal w/
Unicode. I doubt C will ever have the type of "support" for Unicode like,
for instance, Java has. Though it's worth mentioning that arguably Java got
it wrong. Which is why C will never have that type of support; there's no
single way to do it, and it's quite application specific.

- Bill