The OpenNET Project / Index page

[ новости /+++ | форум | теги | ]

Поиск:  Каталог документации | C

[alt.comp.lang.learn.c-c++] - FAQ list

This post contains useful information for anyone wishing to learn C and C++, listing online tutorials and resources, giving book recommendations and helping clear some common misconceptions.
Archive-name: C-faq/learn
Posting-Frequency: monthly
Last-modified: 23 August 1999
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 readers 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. It is posted monthly to
alt.comp.lang.learn.c-c++, comp.lang.c, comp.lang.c++, 
comp.lang.c.moderated, comp.answers, alt.answers and news.answers.

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


Compiled by Sunil Rao <sunil.rao@ic.ac.uk>.
Comments, suggestions, corrections, constructive criticism and requests
 for clarification will be gratefully acknowledged.


Last update: 23 August 1999

Last changes made: Updated and expanded the answers to questions 6,
 10, 15, 16, 17, 18 and 19.
To do list: To add answers to a number of questions and to update
 information regarding compilers.



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, Jerry Coffin, Stuart Hall, Dann Corbit,
 Michael McGoldrick, Cameron Foster, Brody Hurst, Jabari Adisa,
 Wieland StЭbinger, Chris Newton and Bernd Luevelsmeyer
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.

    That probably looks scary. Basically, anybody can post to the
    group. Provided the questions you post are on-topic and the answers
    you provide are accurate, you should not have a problem. If your
    question is off-topic, you will typically be redirected to a
    newsgroup that is more appropriate; if your answers are
    inaccurate, you risk being corrected with a flame.


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.

    It can usually (though not always) be assumed that anybody who
    talks about "C/C++" as one language is no expert - this extends
    to book authors too. It is normally unclear whether somebody is
    referring to "C OR C++" or "C AND C++" when using this expression,
    so it is probably best avoided.


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.

    A lot of people incorrectly believe that object-oriented
    programs cannot be written in C; this is not true. What is true
    is that C++ provides features that make it easier to write in a
    style that is object-oriented; in other words, C++ supports
    programming in an object-oriented style.


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. Most
    regulars on this group show great patience with many common
    beginners' questions and will willingly expound on many topics of
    interest or particular difficulty, referring to appropriate
    reference material, either in printed or in electronic form, as
    necessary.


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.

    If you've been thus redirected, do not get miffed or upset and post
    an angry response - it will cut no ice with the regulars and will
    only label you as an unwilling learner. What's discussed in this
    group is rigidly defined to limit the traffic and make the group
    useful to as wide a possible audience as possible.
 

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 Deja.com, 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.

     Deja.com: http://www.deja.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. A good reference is
       http://www.ezine.com/netiquette.html

     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. There usually is
     a good reason - see question 9.

     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. This is also why it is a very bad idea to email your
     questions directly to regulars; you have no insurance against
     any potential mistakes - remember that nobody is infallible.

     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.

     It usually helps if you indicate in somewhere in your post if
     you're expecting a C or a C++ answer - several techniques
     appropriate to C++ will not work in C, and some C programs will
     not work or are considered bad style under C++. It also makes it
     easier for other readers - they can then safely ignore your post
     if they cannot help you with it. If you're not sure as to which
     language you're learning, you probably need to get better
     resources to learn from.


8: I posted a homework question, but got no help; only sarcastic
responses. Why?
     
     Homework questions are in general not welcome here - most attempts
     to disguise one usually do not work particularly well. You will
     typically receive no help unless you can demonstrate that you have
     made an honest attempt to solve the problem yourself, by posting
     some code you have trouble with, for instance.

     There is little point in a regular supplying you with code to
     fulfil an assignment if you are going to pass the course and come
     out and work on real-world projects without knowing how to even
     tackle a basic homework problem. See also
      http://home.att.net/~jackklein/ctips01.html#homework
      http://members.xoom.com/jshiva/hw.txt


9: 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, and vice-versa. 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. As
     a beginner, it probably makes more sense to concentrate on the
     core language itself and master that before branching off to
     learn system-specific tricks.

     See also http://members.xoom.com/jshiva/offtopic.txt


10: 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, microsoft or
     watcom newsgroups, you might find it necessary to connect
     to forums.borland.com, msnews.microsoft.com or forums.sybase.com
     instead. See also
      http://www.borland.com/newsgroups/
      http://sdn.sybase.com/sdn/appdev/newsgroups.stm

     * 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

      Another avenue worth exploring for general algorithms questions
      might be the bulletin board at the Analysis of Algorithms
      homepage based at http://pauillac.inria.fr/algo/AofA/ and
      mirrored at http://www.cecm.sfu.ca/mirror/INRIA/algo/AofA/.

      There is a real difference between an algorithm and an
      implementation thereof. A question regarding an algorithm itself
      is, strictly speaking, off-topic though issues do get raised here
      in the absence of any good newsgroup to discuss them in.
      Questions relating to implementations are of course on-topic
      here.

     * 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
      Watcom C/C++              powersoft.public.watcom_c_c++.general
      CodeWarrior               comp.sys.mac.programmer.codewarrior

      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


11: 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. Please also specify if your code is C
     or C++.
     
     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. It usually helps if
     you set the warning levels to the highest possible for your
     compiler - let the compiler pick out any errors and warn you of
     any potential problems. And if you post any errors or warning
     messages with your code, it makes it that much easier for a
     regular to see what's wrong with your code - any need to compile
     it yet again will be minimised, especially if the error is a
     common one.


12: 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

     Ted Jensen's tutorial on pointers and arrays in C can be found
     at http://pweb.netcom.com/~tjensen/ptr/cpoint.htm

     Tom Torfs has written an excellent, complete tutorial, meant
     to complement a good introduction to C. It's not primarily
     intended for the complete beginner to the language, though.
      http://members.xoom.com/tomtorfs/cintro.html      

     See also the answer to question 18.
      

13: What should I look for when picking a book to learn from?

     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.

     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.

     The Association of C and C++ Users maintains a collection of book
     reviews taken from its journals. Many of the reviews are fair and
     excellent in their criticism, though there are a few minor
     inconsistencies and a number of truly awful books have escaped
     with favourable reviews. It's a useful starting-point, though.
      http://www.accu.org/bookreviews/public/

     Many C and C++ experts recommend against using ANY book written by
     a certain Herbert Schildt. To see why, read the answer to question
     16. The "Dummies" series of books is not particularly
     well-regarded either in general.


14: What are the best books I can learn C from?

     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.
      http://cm.bell-labs.com/cm/cs/cbook/

     K N King's "C Programming: A Modern Approach" is another text
     frequently recommended on comp.lang.c. This book is a good,
     thorough introduction to C that is a lot easier to work with
     from a beginner's perspective.
      http://knking.com/books/c/

     Another frequently recommended book on C is "C - How to
     Program", 2nd Edition, by H M Deitel and P J Deitel. Please note
     that I have not had a chance to read this book, and include the
     reference on the strength of the the recommendation of a number
     of regular posters to comp.lang.c.
      http://www.deitel.com/products_and_services/publications/chtp2.htm


15: What are the best books I can learn C++ from?

     Before going further, I should mention that I am not a C++
     programmer myself, and the recommendations listed here are based on
     positive comments I have heard from others.

     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.
      http://www.research.att.com/~bs/about_3rd.html

     A more accessible book that is intended for beginners is "C++
     Primer", 3rd Edition, by Stanley Lippman and JosИe 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.
      http://cseng.aw.com/bookdetail.qry?ISBN=0-201-82470-1&ptype=0

     Another text I've seen seen particularly recommended is "C++ - How
     to Program", 2nd Edition, by H M Deitel and P J Deitel. Again, this
     text does not assume prior knowledge of C.
      http://www.deitel.com/products_and_services/publications
                                                            /cpphtp2.htm

     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.
      http://www.libertyassociates.com/book_edit.htm#21 Days
      http://www.bruceeckel.com/books.html#ThinkingInCPlusPlus

     Bruce Eckel has also placed a "beta" of the second edition of his
     "Thinking in C++" online as well. Do remember that it isn't the
     final version and that there might remain some as-yet undetected
     errors.
      http://www.eckelobjects.com/ThinkingInCPP2e.html
     
     The C++ FAQ contains some recommendations for C++ books as well.


16: 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://herd.plethora.net/~seebs/c/c_tcr.html

     The above reviews are admittedly based on two of Schildt's older
     books. However, the language they describe has not changed in the
     intervening period, and several books written at around the same
     time remain highly regarded.
     
     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 25.


17: 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. Make sure you read the FAQ thoroughly
      first, however, and post any questions you have regarding its
      setup to comp.os.msdos.djgpp, not here.
       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/
      Also, for another port, see
       http://www.xraylith.wisc.edu/~khan/software/
                                           gnu-win32/egcs-mingw32.html

      You could also get hold of Bloodshed Dev-C++, which is
      essentially Mingw32 bundled with an editor, packaged in an
      easier-to-use form.
       http://www.bloodshed.nu/devc.html

      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/


     * Pacific C

      The Pacific C compiler is available for free for personal use.
      You can download it from
       http://www.hitech.com.au/products/pacific.html


     * MPW

     If you're programming under the Apple Macintosh, you can obtain
     the Macintosh Programmers' workshop for free.
      http://developer.apple.com/tools/mpw-tools/


     * Turbo C

     Inprise (formerly known as Borland) have commenced making older
     versions of their software available for free download. This
     includes older (possibly pre-standard) versions of their Turbo C
     compiler.
      http://community.borland.com/museum/


     * 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 that it is not wholly compatible with
      the standard. The incompatibilites are well-documented, however.


18: 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.

     For beginners to C (and C++), Jack Klein has put up an excellent
     page with tips, suggestions and expanded answers to a number of
     commonly asked beginners' questions.
      http://home.att.net/~jackklein/c/c_main.html

     The Comeau Computing web site features several highly informative
     and useful resource pages, including
      http://www.comeaucomputing.com/resources/litsuggs.html
      http://www.comeaucomputing.com/faqs/cppfaq.html

     Steve Summit has archived some of his longer and more informative
     Usenet posts at
      http://www.eskimo.com/~scs/readings/index2.html

     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/

     Karim Ratib's well-indexed code page has links to many useful
     resources.
      http://www.iro.umontreal.ca/~ratib/code
     
     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

     Some questions relating to what standard C is all about are
     answered at
      http://lglwww.epfl.ch/~wolf/c/

     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


19: 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 a firm no.

     Look up the C++ FAQ to see why Cline thinks you do not need to
     learn C before C++. A post by Bjarne Stroustrup to comp.lang.c++
     addresses this point too.
       http://www.research.att.com/~bs/learn.html

     "Learning Standard C++ as a New Language" - a paper by Stroustrup
     available from http://www.research.att.com/~bs/papers.html -
     examines this much-debated issue in great depth, but the paper is
     aimed more at educators than at beginners.


20: 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++.

     
21: 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.


22: 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 10 for a list of such groups.


23: 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.


24: 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 12 and 18.


25: 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 16). 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


26: 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 10.

     The sole reason for redirecting compiler setup questions to other
     groups is to reinforce the point that a language is inherently
     separate from an implementation of one. There are simply too
     many different implementations of C and C++, and too many
     subtleties involved in the actual learning of C and C++ for all
     of them to come under the banner of this newsgroup.


27: Which language should I learn first then - 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.

     If you do decide to learn C++, there is little point in learning
     C itself first. See also question 19.

     If you have little or no programming experience, be prepared to
     face a real challenge. C and C++ have enough quirks and subtleties
     to catch out even expert programmers in other languages. It's not
     impossible to learn to program with C or C++ as a first language,
     just more difficult than with Turing, Pascal or a structured
     BASIC, for instance. Programming in C or in C++ is generally
     considered to be a more pleasureable experience than doing so
     in beginners' languages by those experienced in either, but the
     very fact that your freedom is limited and restricted by these
     languages makes them easier to learn.


28: 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 using C++ effectively requires a major mind-shift
     for many C programmers).


29: 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. Usenet style
     in general tends to be terse and to-the-point and this FAQ reflects
     that, while attempting to be as fully informative as possible.

     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!
-- 
{ Sunil Rao }
"...certainly no beast has essayed the boundless, infinitely 
 inventive art of human hatred. No beast can match its range and
 power." - Arundhati Roy, "The God of Small Things", 1997.



Партнёры:
PostgresPro
Inferno Solutions
Hosting by Hoster.ru
Хостинг:

Закладки на сайте
Проследить за страницей
Created 1996-2024 by Maxim Chirkov
Добавить, Поддержать, Вебмастеру