debug assertion failed

rahulsk1947 · 06-13-2009, 06:27 AM

hi,i got the following code.it compiles welll.but when running,it gives a"debug assertion failed" error.

Code:

#include <iostream>

class test{
public:
	char *fileName;
	test(char *r){
		fileName=r;
	}
	~test(){
		delete(fileName);
	}
};
using namespace std;

void main(void){
	test r("xyz");

	system("pause");
}

wrong to have "delete(fileName)" ??

JacobN · 06-13-2009, 06:37 AM

Yep, in that case it is. You should probably use a std::string instead of a char* if it's an option, since it's much easier.

If it's not an option you should perhaps make the parameter in the constructor a const char*.

Maybe then consider allocating enough memory for the char *fileName to hold the content in r. Then copy the content of the r to the newly allocated memory that fileName points to, and then delete this memory in the destructor.

Not sure about the last part, like, if it's a good way to do it... But prefer using std::string over char* for strings.

Elysia · 06-13-2009, 06:49 AM

You can only delete what you new'ed. Because you didn't new the string, you cannot call delete on it. That's why you get the assertion.
Moreover, any string literal should be const char (http://sourceforge.net/apps/mediawik..._be_const_char).
You should not be using void main (http://sourceforge.net/apps/mediawik...itle=Void_main).
You can get rid of the "void" inside void main(void) too.
And an information article on T* vs T *: Stroustrup: C++ Style and Technique FAQ

cyberfish · 06-13-2009, 07:33 AM

Quote:

You can get rid of the "void" inside void main(void) too.

Note that, if my memory serves me correctly, () has different meanings in C than in C++. In C++, () means no argument (same as (void)). In C, () in function prototype means unspecified arguments.

Quote:

And an information article on T* vs T *: Stroustrup: C++ Style and Technique FAQ

IMHO it unnecessarily confuses beginners. There are plenty of people doing it both ways, Beginners usually have more important things to worry about...

Elysia · 06-14-2009, 11:54 AM

Quote:

Originally Posted by cyberfish

Note that, if my memory serves me correctly, () has different meanings in C than in C++. In C++, () means no argument (same as (void)). In C, () in function prototype means unspecified arguments.

But this is C++, so it's unnecessary.

Quote:

IMHO it unnecessarily confuses beginners. There are plenty of people doing it both ways, Beginners usually have more important things to worry about...

I disagree. Many are just shown a particular style and thinks it's the only one.
It's important to choose a style you're comfortable with from the get-go and stick with it IMHO.

Sebastiani · 06-14-2009, 12:00 PM

>> But this is C++, so it's unnecessary.

Personally, I prefer to explicitly declare it void. But as you pointed out, these are just stylistic issues.

iMalc · 06-14-2009, 01:25 PM

Quote:

Originally Posted by rahulsk1947

wrong to have "delete(fileName)" ??

Yes, and wrong to have void main(void). Main must return int:

Code:

int main()

CodeMonkey · 06-14-2009, 03:36 PM

It must return an int, but will do so implicitly if you do not specify a return value. So even though you don't 'return', it's still important to make main() an int.

06-13-2009, 06:27 AM	#1
rahulsk1947 Registered User Join Date: Feb 2006 Posts: 58	debug assertion failed hi,i got the following code.it compiles welll.but when running,it gives a"debug assertion failed" error. Code: #include <iostream> class test{ public: char fileName; test(char r){ fileName=r; } ~test(){ delete(fileName); } }; using namespace std; void main(void){ test r("xyz"); system("pause"); } wrong to have "delete(fileName)" ??
rahulsk1947 is offline

06-13-2009, 06:37 AM	#2
JacobN Registered User Join Date: Nov 2007 Posts: 29	Yep, in that case it is. You should probably use a std::string instead of a char* if it's an option, since it's much easier. If it's not an option you should perhaps make the parameter in the constructor a const char. Maybe then consider allocating enough memory for the char fileName to hold the content in r. Then copy the content of the r to the newly allocated memory that fileName points to, and then delete this memory in the destructor. Not sure about the last part, like, if it's a good way to do it... But prefer using std::string over char* for strings.
JacobN is offline

06-14-2009, 12:00 PM	#6
Sebastiani Guest Join Date: Aug 2001 Posts: 4,923	>> But this is C++, so it's unnecessary. Personally, I prefer to explicitly declare it void. But as you pointed out, these are just stylistic issues.
Sebastiani is offline

06-14-2009, 03:36 PM	#8
CodeMonkey Kiss the monkey. Join Date: Sep 2001 Posts: 810	It must return an int, but will do so implicitly if you do not specify a return value. So even though you don't 'return', it's still important to make main() an int. __________________ "If you tell the truth, you don't have to remember anything" -Mark Twain
CodeMonkey is offline

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
debug assertion failed!	chintugavali	C++ Programming	5	12-21-2007 04:05 AM
debug assertion failed !	blue_gene	C++ Programming	2	05-09-2004 11:23 AM
Debug Assertion Failed!	Ray Schmidt	C++ Programming	3	02-21-2003 09:58 PM
Debug Assertion Failed	minesweeper	Windows Programming	5	12-11-2002 05:11 PM
Debug assertion failed	Bajanine	Windows Programming	4	10-17-2002 04:34 PM