Comments on: 4.3 — File scope and the static keyword http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/ Tue, 07 Feb 2012 12:30:29 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: lynx1241 http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/comment-page-1/#comment-95655 lynx1241 Sun, 03 Jul 2011 16:02:55 +0000 http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/#comment-95655 In english it's called square root. C++ doesn't have a square root operator, like all other programming languages I know. But it does have a sqrt function in the "cmatch" library. In english it’s called square root. C++ doesn’t have a square root operator, like all other programming languages I know. But it does have a sqrt function in the “cmatch” library.

]]> By: jon http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/comment-page-1/#comment-91488 jon Mon, 06 Sep 2010 03:00:47 +0000 http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/#comment-91488 Also, since it is only declared once and not every time the function is called, it conserves memory. Right? Also, since it is only declared once and not every time the function is called, it conserves memory. Right?

]]> By: MrAlshahawy http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/comment-page-1/#comment-91373 MrAlshahawy Sat, 04 Sep 2010 07:13:20 +0000 http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/#comment-91373 Consider Static variable as a combination between Global and Local Variables benefits: Static takes the benefit of keeping its value after you go out of the scope just like Global, At the same time you avoid the downside of Global variable which is that any other functions may change its value causing unpredictable values. Consider Static variable as a combination between Global and Local Variables benefits:

Static takes the benefit of keeping its value after you go out of the scope just like Global, At the same time you avoid the downside of Global variable which is that any other functions may change its value causing unpredictable values.

]]> By: unknown http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/comment-page-1/#comment-90489 unknown Wed, 18 Aug 2010 11:57:13 +0000 http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/#comment-90489 I have read everything so far, but to me they've missed some mathematical signs like the opposite of x^2, like ? (x) I don't know how it's called in english but in dutch it's called: worteltrekken :P But, thx anyway Alex ;) I have read everything so far, but to me they’ve missed some mathematical signs like the opposite of x^2, like ? (x) I don’t know how it’s called in english but in dutch it’s called: worteltrekken :P
But, thx anyway Alex ;)

]]> By: CodeChaos http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/comment-page-1/#comment-86249 CodeChaos Thu, 10 Jun 2010 03:17:14 +0000 http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/#comment-86249 The name "file scope" is technically incorrect. It can even be misleading. For example, consider you have two files, eg.h and eg.cpp: <i>eg.h</i> <pre>static int myvar; //file scope!?</pre> <i>eg.cpp</i> <pre>#include "eg.h" int main() { myvar = 2; //this is OK. what!? return 0; }<!--formatted--></pre> Since eg.h is <b><i>included</i></b> in eg.cpp, anything declared in eg.h as "file scope" will still be accessible in eg.cpp, even though it was in a different source file. This is because both source code files are compiled into the same object (*.o) file. "File scope" should really be "object scope". The name “file scope” is technically incorrect. It can even be misleading. For example, consider you have two files, eg.h and eg.cpp:

eg.h

static int myvar; //file scope!?

eg.cpp

#include "eg.h"

int main()
{
   myvar = 2; //this is OK. what!?
   return 0;
}

Since eg.h is included in eg.cpp, anything declared in eg.h as “file scope” will still be accessible in eg.cpp, even though it was in a different source file. This is because both source code files are compiled into the same object (*.o) file.

“File scope” should really be “object scope”.

]]> By: Tom http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/comment-page-1/#comment-78375 Tom Mon, 15 Feb 2010 17:18:43 +0000 http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/#comment-78375 Brad - The easiest way would be to write the variable to a file at the end of the program, then read it back in again when the program is next run. Brad -

The easiest way would be to write the variable to a file at the end of the program, then read it back in again when the program is next run.

]]> By: Phil Oertel http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/comment-page-1/#comment-78005 Phil Oertel Sun, 07 Feb 2010 03:50:01 +0000 http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/#comment-78005 Alex, thank you for this excellent tutorial! Great explanation of what is otherwise quite a tricky set of concepts. Alex, thank you for this excellent tutorial! Great explanation of what is otherwise quite a tricky set of concepts.

]]> By: Brad http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/comment-page-1/#comment-76998 Brad Sat, 23 Jan 2010 03:21:25 +0000 http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/#comment-76998 I assume static variables reset every time the program is exited? Is there a way to keep a variables value even after the program ends? Say for instance you wanted to create a counter that keeps up with how many time a program was run or a particular function was called? I assume static variables reset every time the program is exited? Is there a way to keep a variables value even after the program ends? Say for instance you wanted to create a counter that keeps up with how many time a program was run or a particular function was called?

]]> By: earlmw http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/comment-page-1/#comment-75238 earlmw Fri, 01 Jan 2010 01:35:26 +0000 http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/#comment-75238 It really has since the original K&R C programming It really has since the original K&R C programming

]]> By: Falcon http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/comment-page-1/#comment-75044 Falcon Tue, 29 Dec 2009 14:29:03 +0000 http://www.learncpp.com/cpp-tutorial/43-file-scope-and-the-static-keyword/#comment-75044 Yes these variables will be having global scope. If you are declaring variables in source1.h they should be preceded with "extern" keyword. Yes these variables will be having global scope. If you are declaring variables in source1.h they should be preceded with “extern” keyword.

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