Error C2065 undeclared identifier

[pasta]

I this error while trying to use the identifier that is declared into another header. I have included this header in the cpp and still complains.

[JosAH]

I this error while trying to use the identifier that is declared into another header. I have included this header in the cpp and still complains.

So you did something like:

header file:

#ifndef MYHEADER_H
#define MYHEADER_H
extern int foo;
#endif
 

source file(s):

#include "myheader.h"
...
foo= 42;
 

Did you actually *define* your variable "foo" in exactly one .cpp file? If not the
linker will keep complaining.

kind regards,

Jos

[pasta]

So you did something like:

header file:

#ifndef MYHEADER_H
#define MYHEADER_H
extern int foo;
#endif
 

source file(s):

#include "myheader.h"
...
foo= 42;
 

Did you actually *define* your variable "foo" in exactly one .cpp file? If not the
linker will keep complaining.

kind regards,

Jos

more like

for (int y = 0; y < foo; y++)

[pasta]

more like

for (int y = 0; y < foo; y++)

where foo is the number of lines I'm reading into memory.

[JosAH]

where foo is the number of lines I'm reading into memory.

That all is fine but where (in which .cpp file) did you *define* that foo variable?
Header files tell the compiler that somewher such a foo variable is defined and
the compiler believes you but you do have to define it once somewhere in a .cpp
file.

kind regards,

Jos