Global Variable Problem

[Caoimh]

I need to initialise the global variables, so when I attempt the following, an error message appears.Any suggestions appreciated in stdafx.cpp file #include "stdafx.h" int g_SomeGlobalVariable = 0; and in stdafx.h file extern int g_SomeGlobalVariable = 0;

[Manfred Staiger]

Omit the "extern int g_SomeGlobalVariable" in the header file. You must use this "extern"-statement in the files from which you want to access your global variable (it's only for the linker). MS

[Robert A T Kaldy]

You needn't to do that. Let the declaration in the stdafx.h (because stdafx.h is included in all source files generated by AppWizard), but omit the initialization ( = 0). Global and static variables must be initialized only in the source file. Robert-Antonio "Czech Railways discovered, that in case of disaster the most damaged wagons were the first and the last. So they decided to create trains without them."

[Manfred Staiger]

I don't know if you are completely right. Certainly, you get an errormessage on an assignment in a header file. But in this case I wouldn't be amazed if the whole "extern"-statement is a problem, because his globalVar isn't "extern" in this case. I didn't try out. Anyhow, I wouldn't place an "extern"-statement in the stdafx.h, even because it is included everywhere else. But that's a question of the point of view. MS

[BIG_MG]

Another way of doing the same would be declare it static. So in the stdafx.h you can write like static int gi_var = 0;

[Tim Smith]

That wouldn't be a true global variable then. That makes n variables all with file scope. Tim Smith I'm going to patent thought. I have yet to see any prior art.

[Tim Smith]

There is nothing wrong with declaring a variable extern and then defining it in the same compilation module. Tim Smith I'm going to patent thought. I have yet to see any prior art.