Receiving junk (??) when returning a string from a function ...
Author
Hello... The score for my game is an integer, and I have a function that prints text as strings... I''m trying to convert the score to a string, and return it from a member function of my class....
For some reason the only thing that ever shows up is a "g" and not the score integer...
Any ideas why?
Here''s the code that returns the score as a string:
char* getScoreAsString(void) { char buff[11]; return itoa(score, buff, 10); }
This is how I am passing it into my print text function:
printString(listbase, gf->getScoreAsString());
I know the printString function works because if i substitute what I have there with "2003" it works wonderfully.
Problem must be in how I''m returning the string.
Help is appreciated!
Thanks...
-Dennis
char buff[11];
is a LOCAL variable, it will only be valid for as long as the program is inside getScoreAsString() - as soon as you exit that function, anything can happen to that memory - it might remain ok if you''re lucky; it might get totally trashed; it might get partially trashed. The reason it''ll be trashed is local variables used in any function or created AFTER getScoreAsString() has returned will use the SAME memory.
As a simple solution make "char buff[11];" global - or better, rethink your design so that you aren''t returning locally allocated memory from a function.
Declaring it as a static would make the code look a bit nicer than a global (same thing* as a global after compilation though...)
[*]<br> <br><br>–<br>Simon O''Connor<br>Creative Asylum Ltd<br><A HREF="http://www.creative-asylum.com">www.creative-asylum.com</A>
is a LOCAL variable, it will only be valid for as long as the program is inside getScoreAsString() - as soon as you exit that function, anything can happen to that memory - it might remain ok if you''re lucky; it might get totally trashed; it might get partially trashed. The reason it''ll be trashed is local variables used in any function or created AFTER getScoreAsString() has returned will use the SAME memory.
As a simple solution make "char buff[11];" global - or better, rethink your design so that you aren''t returning locally allocated memory from a function.
Declaring it as a static would make the code look a bit nicer than a global (same thing* as a global after compilation though...)
[*]<br> <br><br>–<br>Simon O''Connor<br>Creative Asylum Ltd<br><A HREF="http://www.creative-asylum.com">www.creative-asylum.com</A>
Functions returning pointers are dangerous... especially in your context. 
Don''t treat char* as string, because it isn''t. Integer works because it isn''t a pointer.
Give std::string a try.
If you still wanna try on char*, I suggest this approach:
Don''t treat char* as string, because it isn''t. Integer works because it isn''t a pointer. Give std::string a try.
If you still wanna try on char*, I suggest this approach:
void getScoreAsString(char *outbuf, int score){ itoa(score, buff, 10); } 
quote:Original post by S1CA
[*]<br> <hr height=1 noshade></SPAN></BLOCKQUOTE> <br><br>Thread-safety ? <img src="smile.gif" width=15 height=15 align=middle><br> <br><br><hr><tt><small>[ <a href="http://www.gamedev.net/reference/start_here/">Start Here !</a> | <a href="http://www.tuxedo.org/%7Eesr/faqs/smart-questions.html">How To Ask Smart Questions</a> | <a href="http://www.accu.org/bookreviews/public/reviews/0hr/">Recommended C++ Books</a> | <a href="http://www.parashift.com/c++-faq-lite/">C++ FAQ Lite</a> | <a href="http://www.function-pointer.org/">Function Ptrs</a> | <a href="http://search.freefind.com/find.html?id=8028742&m=0&p=0">CppTips Archive</a> ]<br>[ <a href="http://www.gamedev.net/reference/programming/features/orgfiles/">Header Files</a> | <a href="http://www.wotsit.org">File Format Docs</a> | <a href="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccore/html/LNK2001.asp">LNK2001</a> | <a href="http://www.sgi.com/tech/stl/">C++ STL Doc</a> | <a href="http://www.stlport.org">STLPort</a> | <a href="http://www.bloodshed.net/devcpp.html">Free C++ IDE</a> | <a href="http://www.boost.org">Boost C++ Lib</a> | <a href="http://www.dinkumware.com/vc_fixes.html">MSVC6 Lib Fixes</a> ]</small></tt>
The other posters are correct (I especially encourage the use of std::string), but for a straight answer to your question: char buff[11]; allocates the array statically, which means that the memory is deallocated at function exit. If you wish to return a valid pointer, you will have to allocate the memory dynamically: char* buff = new char[11];
Heh, someone shoudl tell my C Programming Lecturer that, i told him and his resonse was "Well, its worked for me so far, so i see no reason to change it". Madness...
This topic is closed to new replies.
Advertisement
Popular Topics
Advertisement
