Thread: symbol "NULL" not found????

my program compiles fine. but when i run it i get an error. it points to this line

Code:

if (FAILED(lpDD->CreateSurface(&ddsd, &DDSPrimary, NULL)))

but when i try to check the result of failed with a quickwatch( im using VC++ 6.0) it says: symbol "NULL" not found. if i use a quickwatch on just the NULL part it says the same thing. i dont understand stand it. if it says that, why did it compile? maybe i need to reinstall VC++. anyone have any ideas???

TIA
Echo

NULL has to be defined. Although, usually it is already. I don't know, I don't use VC++.

how would i define NULL??

Put this in your #defines (usually below #includes but above globals).

#define NULL 0

Some people cast it as a pointer to void, but for most uses 0 is fine.

In "The C++ Programming Language" by Bjarne Stroustrup.... Bjarne says,

In C, it has been popular to define a macro NULL to represent the zero pointer. Because of C++'s tighter type checking, the use of plain 0, rather than any suggested NULL macro, leads to fewer problems. If you feel you must define NULL, use

Code:

const int NULL = 0;

Wow, a thread about nothing!

Use one of these (but not the const int thing)

Code:

#define NULL 0
//or
#define NULL 0L
//or
#define NULL ((void *)0)

The seconde one is really not necessary since an int is long in win32. And the third is actually not all that uncommon. But this assumes that NULL is always a pointer. If I were you I would cut this and put it in my code

Code:

#ifndef NULL
#define NULL 0
#endif

NULL is defined in stdio.h