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variable scope (basic easy question)

Started by Scooter Oct 12, 2000 at 9:47 PM 2 replies 200+ views

Original Post

Oct 12, 2000 at 9:47 PM

I have two .cpp files and in the first one there''s the : LPDIRECTDRAW7 g_ddraw = NULL; how can i access g_ddraw in the second .cpp file so i can call g_ddraw->GetDisplayMode() ? or do i have to pass the value as a parameter through every function till the one i want to use it in ?

Sly

Oct 12, 2000 at 10:22 PM

In the header for the first source file, add the line

extern LPDIRECTDRAW7 g_ddraw;

In the second .cpp file, include the first .h file.

Steve 'Sly' Williams
Tools Developer
Krome Studios

IOFILE

Oct 13, 2000 at 12:15 AM

I agree completely with Sly. Create the the global in one cpp file and then refer to it with the keyword extern from an h file, and include that in all of the files that need to use the variable. For example:

dd.cpp

LPDIRECTDRAW7 g_ddraw = NULL;
...

dd.h

extern LPDIRECTDRAW7 g_ddraw;
...

ddsurface.cpp

#include "dd.h"
...
g_ddraw->...
...

hope the example helped

Scooter

Author

Scooter

Oct 13, 2000 at 1:56 PM

yeah that helps if they''re both .cpp files and no .h files i can just put:extern LPDIRECTDRAW7 g_ddraw; at the top the second .cpp file right ?

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