[alt.comp.lang.learn.c-c++] - FAQ list
Sunil Rao
Posting-Frequency: monthly
Last-modified: 30 October 1998
URL: http://www.raos.demon.co.uk/acllc-c++/faq.html
This document is a FAQ list for the newsgroup alt.comp.lang.learn.c-c++.
It provides you with a framework and a set of guidelines for posting
here, in addition to answering a number of questions newcomers here tend
to ask.
This FAQ is meant to be read in its entirety.
This is the plaintext version of this list.
An HTML version can be located at
http://www.raos.demon.co.uk/acllc-c++/faq.html
Written by Sunil Rao <suni...@ic.ac.uk>.
Comments, suggestions, corrections and constructive criticism will be
gratefully acknowledged.
Last update: 30 October 1998
Last changes made: Modified the answer to Q 9
Special Thanks to...
Dennis Swanson, Jim Gewin, Billy Chambless, Mark Brown, Dave Dunfield,
Jack Klein, Steve Summit, Steve Clamage, Dennis Ritchie, Kaz Kylheku,
Lars Hecking, Pablo Halpern and Jerry Coffin
for their helpful comments, suggestions, advice, corrections and
constructive criticism, and (in the case of some) for permitting me to
quote from their papers/posts.
1: What is the purpose of this newsgroup?
alt.comp.lang.learn.c-c++ is an unmoderated newsgroup for the
discussion of issues that concern novice and non-expert programmers
in C and C++ who wish to *LEARN* more about one or both of these
languages.
2: What is C/C++?
First of all, C and C++ are different languages. C was created by
Dennis Ritchie as an efficient language for systems programming.
Bjarne Stroustrup then extended C by adding features to support
object-oriented programming. C++ can be considered to be a
superset of C, but there are real differences between them.
3: So, are C and C++ not so similar after all?
They are indeed similar to a great extent. Incompatibilities do
exist, though, and many idiomatic constructs used in C are frowned
upon by C++ experts. C++ programmers generally consider code that
does not exploit those features of C++ that make it possible to
write better programs - programs that are more readable and easier
to write and maintain - to be in poor style. The differences
between the two languages are significant enough to ensure that
one has to be clear about the language being used. However, it
must not be forgotten that C++ is a largely a superset of C, and
that it is possible (though perhaps not desirable) to write code
that works correctly in both languages.
4: What is the difference between this newsgroup and comp.lang.c or
comp.lang.c++?
This newsgroup is primarily intended for discussion related to the
LEARNING of C and C++. The other two groups are primarily intended
for discussion of the features of the respective languages
themselves. Naturally, some overlap does occur. This group does tend
to be slightly (perhaps excessively so) more informal, though.
5: What kind of questions may be asked here?
Any question relating to any aspect of C or C++ that you're having
trouble understanding is on topic here. By C, what is meant is the
language PROPER and its standard library as defined by ANSI and ISO.
C++ discussions are about the proposed language standard (that
recently passed its formal vote) and the library it defines. Any
questions relating to specific compilers, third-party or non-
standard libraries, compiler extensions etc are unwelcome here, and
will probably be answered with a redirection to a more appropriate
newsgroup.
6: I have a burning question about XXX. What should I do first?
First of all, do check to see if your question has not been been
answered before. Look up any of the standard references on the
language. If you can't find the answer, browse the group, lurk here
for a few days, search the archives at Dejanews, read the relevant
FAQs (including those of comp.lang.c and comp.lang.c++), and if you
STILL can't find the answer, post by all means.
Note that you might not be the first ever learner to have run into
your problems. There is a good chance that your question has been
answered before.
Dejanews: http://www.dejanews.com/
C FAQ: http://www.eskimo.com/~scs/C-faq/top.html
C++ FAQ: http://www.cerfnet.com/~mpcline/c++-faq-lite/
7: What other points should I make note of BEFORE posting here?
Please observe basic Netiquette guidelines. If you're not sure of
what these are, subscribe to news.announce.newusers, and read *ALL*
of the posts there.
To summarise these points very briefly - ensure that your post is
on topic. Do your homework before posting. Don't post the same
question one hundred times. Don't troll. Don't post homework
questions without anything to show your effort. Don't ask for
replies to be sent by email. Don't post binaries. Make sure that
your subject line is an accurate description of the problem/topic.
Please do not ask for replies by email. If you haven't got the time
or patience to read the newsgroup, that's tough. The answers you
receive might benefit other readers of the newsgroup as well, and
you yourself might learn more from the discussions your question
might generate.
If you have to reply, be accurate and precise - your reply is being
read by LEARNERS, remember. If you are unsure or have nothing new
to add, don't bother.
For heaven's sake, don't get abusive when you are corrected or
redirected. If you are unsure as to why you have been redirected,
ask the person who did so *PRIVATELY* by email.
Do not take any answers on trust. Sadly, many of those who post
answers here know even less than the interested learner who posted
the original question. Wait for a few days before relying on any
posted code or answers, just in case they might be corrected by
others.
Please do not make any MIME or UUENCODED posts (this includes
HTML). Many newsreaders cannot handle such posts correctly. You
will only make it impossible for many to read your posts.
And please try not to flame. This is a learners' group. Not
everyone who posts here is aware of all the issues involved. A
grumpy attitude only makes things difficult for everyone
concerned.
8: Why are questions relating to Windows, Graphics, Sockets etc. off-
topic here?
Questions on these topics come up every so often here. C and C++
are languages, not operating systems. They come with limited,
though highly useful, standard libraries. While any question
relating to these libraries is relevant and most certainly on
topic, a question relating to MFCs, for instance, is of absolutely
no interest to a Unix expert. There exist newsgroups DEVOTED to
these non-standard additions. It certainly makes more sense to post
a question in a place where there is a greater chance of it being
answered, and answered correctly.
9: What are some other related groups where I might post questions?
(Answer adapted from the regular "Welcome to comp.lang.c" post
by Billy Chambless and Tim Behrendsen)
You *really* ought to be able to work out where to post by
yourself. Please, please, please, for heavens' sake read the
FAQs and lurk for a while before posting your questions.
Please do not post to more groups than are necessary. Think
carefully about the relevance of your post before you post to any
of the newsgroups mentioned below. If you decide that your question
is indeed relevant to more than one newsgroup and is not a FAQ,
please cross-post rather than multi-post. Remember that many
regular readers of this newsgroup also follow several of the other
groups mentioned below.
Note: if your news server does not carry the borland.* newsgroups
or the microsoft.* groups, you might find it necessary to connect
to forums.borland.com or msnews.microsoft.com instead.
* Language Issues
C comp.lang.c, comp.lang.c.moderated
C++ comp.lang.c++.moderated, comp.lang.c++
x86 assembly comp.lang.asm.x86
* Non-language-specific Issues
Algorithms comp.programming
Graphics comp.graphics.algorithms
* Compilers/Libraries
The gcc compiler gnu.gcc
DJGPP (gcc for DOS) comp.os.msdos.djgpp
Borland C++ borland.public.cpp
borland.public.cpp.language
Borland C++Builder borland.public.cppbuilder
borland.public.cppbuilder.language
Visual C++ microsoft.public.vc.ide_general
microsoft.public.vc.language
MFC microsoft.public.vc.mfc
comp.os.ms-windows.programmer.tools.mfc
OWL borland.public.cpp.owl
comp.os.ms-windows.programmer.tools.owl
VCL borland.public.cppbuilder.vcl
* Operating Systems/System Specifics
DOS issues comp.os.msdos.programmer
MS Windows comp.os.ms-windows.programmer.misc
microsoft.public.win16.programmer.*
microsoft.public.win32.programmer.*
OS/2 comp.os.os2.programmer.misc
Macintosh comp.sys.mac.programmer.misc
General UNIX comp.unix.programmer
Amiga comp.sys.amiga.programmer
10: HELP! My program does not work correctly. What do I do now?
Before posting code here, try and make sure that it at least
compiles correctly, even if it does not quite behave the way you
intended it to. Try and localise your error to a particular
function or section of code - most readers have no time to wade
through pages of code (If you are unable to do this, you probably
need to start again from scratch anyway.). Do NOT under any
circumstances post all of your code as an attachment - many will
simply ignore your post.
Essentially, post the smallest complete program that manifests the
problem. This makes it easier for the reader to answer your
question. You might find that doing this enables you to answer
your question yourself!
Read the answer to the above question as well. And do learn how to
use the debugger that came with your compiler.
11: What online tutorials exist for learning C and C++?
The best online tutorial for C I have come across has got to be
Steve Summit's class notes for the C courses he teaches.
http://www.eskimo.com/~scs/cclass/cclass.html
There are references to other C tutorials in his C FAQ as well.
Vinit Carpenter maintains a list of resources for learning C
and C++. Do note, however, that a fair number of the tutorials
placed online contain mistakes and/or are out of date.
http://www.cyberdiem.com/vin/learn.html
See also the answer to question 15.
12: What are the best books that teach C or C++?
Opinions vary widely. Most readers recommend the book(s) they
learnt from, regardless of whether or not they might actually be
suitable for the learner. The fact that many commonly recommended
books are either full of errors or hopelessly out of date (or
even both!) makes matters worse.
Beware of books that claim to teach you both C and C++ - they might
end up teaching you a horrible hybrid instead. It is also probably
better to stick to books that conform to the C and C++ standards,
at least while beginning. Many compiler-specific books do not go
into sufficient depth regarding important language issues and
usually fail to be clear as to whether something is specific to the
compiler under consideration or not.
Some texts come bundled with compilers - it's usually worth
checking to see how out-of-date the compiler actually is. For C,
this is probably less of an issue than it is for C++, simply
because compiler writers have had over a decade to catch up with
the standard.
It pays to keep more than one good book handy; many books known for
their technical accuracy can seem dense and unreadable in places,
and you might at times need to back up a primer with a reference.
If you wish to learn C, the classic text - the "Bible" - is "The C
Programming Language", 2nd Edition, by Brian Kernighan and Dennis
Ritchie. This hallowed text describes and explains ANSI C. K&R2 is
renowned for its brevity, clarity, elegance and completeness; but
these very factors can make it heavy going for the beginner.
K N King's "C Programming: A Modern Approach" is another text
frequently recommended on comp.lang.c. This book is reputed to be a
good, thorough introduction to C that is a lot easier to work with
from a beginner's perspective.
The C++ equivalent of K&R2 is "The C++ Programming Language", 3rd
Edition, by Bjarne Stroustrup. Experienced C++ programmers love it;
however, many beginners seem to find it very hard going indeed.
Like K&R2, it assumes basic familiarity with programming concepts
and is not really intended for the absolute beginner. It does not
assume any previous knowledge of C.
A more accessible book that is intended for beginners is "C++
Primer", 3rd Edition, by Stanley Lippman and Josée Lajoie. This
book is thorough, and conforms to the C++ standard. It is
reportedly extremely clear and detailed, and, again, does not
assume any previous knowledge of C.
Other texts I have seen recommended a number of times on the C++
newsgroups include the badly-named-though-often-recommended "Teach
yourself C++ in 21 days" by Jesse Liberty, "C++ Primer Plus" by
Stephen Prata, and "Thinking in C++" by Bruce Eckel.
The C++ FAQ contains some recommendations for C++ books as well.
Note that I have not read all of these books. These recommendations
are based primarily on the positive comments made by others.
Do make sure that you get the latest edition of any of these books
you decide to purchase. Also please check to see if there is an
errata list available online for any book you decide on; this is
particularly important for programming language texts. It pays to
be suspicious of books for which such lists cannot be located
online for whatever reason.
Many C and C++ experts recommend against using ANY book written by
a certain Herbert Schildt. To see why, read the answer to the
following question.
13: Why do many experts not think very highly of Herbert Schildt's
books?
A good answer to this question could fill a book by itself. While
no book is perfect, Schildt's books, in the opinion of many
gurus, seem to positively aim to mislead learners and encourage
bad habits. Schildt's beautifully clear writing style only makes
things worse by causing many "satisfied" learners to recommend his
books to other learners.
Do take a look at the following scathing articles before deciding
to buy a Schildt text.
http://www.lysator.liu.se/c/schildt.html
http://www.solon.com/~seebs/c/c_tcr.html
The following humorous post also illustrates the general feeling
towards Schildt and his books.
http://www.qnx.com/~glen/deadbeef/2764.html
There is exactly one and ONLY one C book bearing Schildt's name on
its cover that is at all recommended by many C experts - see Q 22.
14: Where can I get a free C or C++ compiler?
(Answer adapted from Joe Buck's FAQ for g++ and libg++.)
* gcc
gcc is a free C and C++ compiler from the Free Software
Foundation available for many Unix-based systems. Its ports for
other systems are also freely available.
http://www.fsf.org/software/gcc/gcc.html
ftp://prep.ai.mit.edu/pub/gnu/
egcs (the experimental gnu compiler system) is another free
project (based on gcc). Check out
http://www.cygnus.com/egcs/
The MS-DOS port (DJGPP) of gcc runs on a 386 or higher, and is a
full 32-bit compiler.
http://www.delorie.com/djgpp/
For a port of gcc that works on 32-bit Windows, look at
http://www.cygnus.com/misc/gnu-win32/
For the Amiga, BeOS, and pOS, look at the GG port of gcc at
http://www.ninemoons.com/GG/
EMX is a port of gcc to OS/2 that also works on DOS.
http://www.os2ss.com/unix/emx09c/
* lcc
lcc-win32 is a free C compiler available for 32-bit Windows.
http://www.cs.virginia.edu/~lcc-win32/
It is based on the retargettable lcc system.
http://www.cs.princeton.edu/software/lcc/
* Micro-C
If you are looking for a free C compiler for MS-DOS that is easy
to install and use, take a look at Micro-C, available from
http://www.dunfield.com/
Do bear in mind, however, that it is not wholly compatible with
the standard. The incompatibilites are well-documented, however.
15: What good websites/online references exist for C and C++?
http://www.lysator.liu.se/c/ is an excellent resource for C,
containing a number of extremely useful links and pointers.
Check out the C++ Virtual Library for some useful C++ links.
http://www.desy.de/user/projects/C++.html
You may wish to look at the C Language Online Journal at
http://www.cs.wustl.edu/~jxh/CLOJ/
For some useful code snippets (some portable; others not),
check out Bob Stout's SNIPPETS archive at
http://www.snippets.org/
Martin Leslie's C Programming reference site is at
http://www.gator.net/~garyg/C/c.html
Jamie Blustein's C Programming Language resources are at
http://www.csd.uwo.ca/~jamie/.Refs/C-refs.html
Scott McMahan's C Programmer's Notebook, which discusses a
number of issues C programmers encounter as their experience
grows, is at
http://www.skwc.com/essent/prognotebook.html
Also, check out
The Mining Company's C/C++ site,
http://cplus.miningco.com/
Jon Morris Smith's C++ resources directory,
http://www.cs.bham.ac.uk/~jdm/cpp.html
Robert Davies' list of online C++ references,
http://nz.com/webnz/robert/cpp_site.html
The #C++ site,
http://www.cl.ais.net/morph/c++/main.html
and Simo Salminen's Programmers' Oasis C and C++ page.
http://www.utu.fi/~sisasa/oasis/oasis-cc++.html
16: Should I learn C before learning C++?
According to a number of C++ experts, including its creator Bjarne
Stroustrup, and Marshall Cline (the author of the C++ FAQ), the
answer is no.
Look up the C++ FAQ to see why Cline thinks you do not need to
learn C before C++.
17: What is the difference between C++ and Visual C++?
C++ is a programming language. Visual C++ is Microsoft's
implementation of it. When people talk about learning Visual C++,
it usually has more to do with learning how to use the programming
environment, and how to use the Microsoft Foundation Classes (MFCs)
for Windows rather than any language issues. Visual C++ can and
will compile straight C and C++.
18: What is portability? Why are so many people concerned about it?
C and C++ are languages that are not tied down to a particular
platform. This means that, with care, it is possible to write useful
code in either of these languages that will run on different
platforms without modification.
That is not to say that ALL code written in these languages must
conform strictly to the standards - in practice it is sometimes
neither possible nor desirable to achieve this aim. However, the job
of porting code is made easier when any system-specific stuff is
carefully packaged or abstracted away, so that it is clear and
straightforward to make the necessary changes during a port.
In order to be able to do this effectively, it is important to be
aware of what can and can not be done within the realms of the
standards set by these languages. That is why a lot of importance is
placed on adhering strictly to the standards, at least while
learning.
19: How do I BEGIN to write C or C++ under Visual or Borland C++?
This question is, strictly speaking, off-topic, but is answered
here since it's one that seems to plague many beginners.
To start with, you need to make sure that you are not writing a
Windows application. Try creating a new project or application
to target MS-DOS, QuickWin or Win32 Console depending on your
compiler version. You can then use the Standard C and C++
libraries to write strictly conforming programs. It's best to
learn to write standard-conforming programs first before
branching off into writing Windows programs.
If you find that you are having a lot of trouble setting up your
compiler, a good place to ask questions is a newsgroup devoted to
your compiler. See Question 9 for a list of such groups.
20: HELP! My program seems to compile correctly, but when it runs, a DOS
window flashes and then vanishes.
This can sometimes occur when you are developing programs using an
IDE. A command prompt window opens and displays the output, and
control is passed back immediately to the IDE.
To get around this, you can look through the various menus to find
a "View Output Screen" option. Alternatively, you could open a
command prompt window and change directory to the one your
executable is going to end up in and run your executable directly
from there.
The solution of using a non-standard function to keep the
executable running until a key is pressed is not a very good idea -
especially if you are going to run your program outside of the
development environment.
21: Why doesn't this FAQ cover language issues?
This is because other better, more comprehensive resources exist
for this purpose. See the answers to questions 11 and 15.
22: Where can I obtain a copy of the standards for C and C++?
You cannot obtain copies of the standards for free. This is because
the standards organisations earn a large part of their revenue from
selling printed copies.
The C FAQ tells you how you can obtain copies of the C standard.
You could also buy "The Annotated ANSI C Standard", by the
afore-mentioned Herbert Schildt (question 13). Make sure that you
ignore the annotations completely, however.
The C++ standard can be obtained online directly from the ANSI
Electronic Standards store . After registering yourself for free,
you can download the document in Adobe PDF format on payment of
$18.00 (US) by credit card.
http://webstore.ansi.org/ansidocstore/default.asp
The standards documents can be daunting at first sight; meant as
they are to be as formal and precise as possible. They are NOT
suitable for learning from, but are intended rather to be used as
the ultimate authority to check with on any language issue.
Also, check the comp.std.c++ FAQ.
http://reality.sgi.com/austern_mti/std-c++/faq.html
23: HELP! I get errors when I try to compile "hello, world"!
Check your source to make sure you haven't missed any semi-colons
or braces. Also remember that C and C++ are case-sensitive - Main()
and main() are completely different, for instance. If you are
satisfied that the program source is all right, then you probably
have not set your compiler up properly. You might need to ask one
of the experts in a newsgroup devoted to your compiler about this -
see the answer to question 9.
24: Which language should I learn first - C or C++?
The answer to this depends on your own inclinations. C is a
smaller, less complex language than C++, and is consequently easier
to master. However, it is probably easier to get up to speed with
C++, if you make effective use of the standard library. Some find C
to be more elegant than C++, others think it to be too "unsafe".
C++ programmers generally feel that it has features that make it
easier to write good, robust, readable and maintainable code in
than in C.
25: Why are C and C++ so popular and widely-used?
(First part of answer adapted from a March 1998 comp.lang.c post
by Kaz Kylheku on "Why Has C Proved To Be Such A Succesful
Language")
C has always been a language that never attempts to tie a
programmer down - it allows for easy implementation, it comes with
a genuinely useful standard library that can itself be implemented
in C, and it is both efficient and portable. C has always appealed
to systems programmers who like the terse, concise manner in which
powerful expressions can be coded. C was widely distributed with an
Operating System (Unix) that was actually largely written in C
itself. Also, C allowed programmers to (while sacrificing
portability) have direct access to many machine-level features that
would otherwise require the use of Assembly Language.
As Dennis Ritchie writes in his paper, "The Development of the C
Language",
C is quirky, flawed, and an enormous success. While accidents
of history surely helped, it evidently satisfied a need for a
system implementation language efficient enough to displace
assembly language, yet sufficiently abstract and fluent to
describe algorithms and interactions in a wide variety of
environments.
C++ has its basis in C - extending it by supporting features meant
to encourage and support the development of large programs. Perhaps
most importantly, it supports object-oriented programming in a
familiar setting and framework (that of C). When C++ was created,
one of the initial aims was to retain compatibility with C to as
large an extent as possible, and retain its spirit and efficiency.
It was possible to convert from C to C++ gradually, thus making use
of C++ (initally, at least) as a "better C", and moving on to
using other features. This allowed many C programmers to learn C++
quickly (though it required a major mind-shift).
26: Why is this FAQ so grumpy/terse/curt/unfriendly?
A lot of questions posted in alt.comp.lang.learn.c-c++ are posted
by people who are generally unsure about what they are learning.
Many beginners fail to appreciate that C and C++ are used on a
number of platforms, and that what works with a particular compiler
is not necessarily going to work with another, even on the same
platform. It is important that a learner be clear about the
differences between programming in standard C or C++, and
programming using platform- and compiler-specific extensions. In
the long run, this approach - that of separating the idea of
"language" and "platform" - leads to a better understanding of both
the language and the platform. It is generally accepted that the
sooner this is appreciated by the learner, the better.
This is the only reason for grumpiness - most interested learners
find alt.comp.lang.learn.c-c++ a very pleasant and helpful place
once they understand this. The newsgroup is nowhere near as grumpy
as this FAQ might suggest - certainly not towards someone who has
read and understood all it has to say!