C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Array declaration question          C++Talk.NET Forum Index -> C++ language, library and standards View previous topic :: View next topic   Author Message dave.lowe@gmail.com Guest Posted: Wed Dec 08, 2004 8:20 pm    Post subject: Array declaration question I've been very use to the requirement of using a constant expression for array size during array declaration. I was just told that the C++ standard allows the following: ... void foo(int n) { int myArray[n]; for (int i = 0; i < n; myArray[i++] = 0); } int main() { int arraySize = 1000; foo(arraySize); return 0; } Now, this *seems* to be just plain wrong; however, some c++ compilers accept it, while some don't. I thought the standard stated you must use a constant expression. Can anyone please tell me what the actual standard says is legal (regardless of how compilers implement it)? Thanks! --- [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://www.jamesd.demon.co.uk/csc/faq.html ] Back to top Alf P. Steinbach Guest Posted: Wed Dec 08, 2004 8:47 pm    Post subject: Re: Array declaration question * [email]dave.lowe (AT) gmail (DOT) com[/email]: Quote: I was just told that the C++ standard allows the following: .. void foo(int n) { int myArray[n]; for (int i = 0; i < n; myArray[i++] = 0); } That's incorrect. It is allowed in C99 (C is not C++, and C99 is not previous versions of C). Quote: Can anyone please tell me what the actual standard says is legal (regardless of how compilers implement it)? n must be a compile-time integral constant, except when you allocate the array dynamically. -- A: Because it messes up the order in which people normally read text. Q: Why is it such a bad thing? A: Top-posting. Q: What is the most annoying thing on usenet and in e-mail? --- [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://www.jamesd.demon.co.uk/csc/faq.html ] Back to top Andrew Koenig Guest Posted: Wed Dec 08, 2004 10:26 pm    Post subject: Re: Array declaration question <dave.lowe (AT) gmail (DOT) com> wrote Quote: I was just told that the C++ standard allows the following: void foo(int n) { int myArray[n]; for (int i = 0; i < n; myArray[i++] = 0); } It doesn't. Whoever told you that is mistaken. --- [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://www.jamesd.demon.co.uk/csc/faq.html ] Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         C++Talk.NET Forum Index -> C++ language, library and standards All times are GMT Page 1 of 1   Jump to: Select a forum C/C++----------------C LanguageC Language (Moderated)C++ Language (Moderated)C++ language (comp.lang.c++)C++ language, library and standards Non-English C/C++ Newsgroups----------------C++ (German)C++ (French)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.