Static variables in C and C++

Question

Is there any difference between a variable declared as static outside any function between C and C++. I read that static means file scope and the variables will not be accessible outside the file. I also read that in C, global variables are static . So does that mean that global variables in C can not be accessed in another file?

Answer 1

No, there's no difference between C and C++ in this respect.

Read this SO answer about what static means in a C program. In C++ there are a couple of other meanings related to the use of static for class variables (instead of instance variables).

Regarding global vars being static - only from the point of view of memory allocation (they are allocated on the data segment, as all globals are). From the point of view of visibility:

static int var;    // can't be seen from outside files
int var;           // can be seen from outside files (no 'static')

Answer 2

There are two concepts here "static linkage (or scope)" and static allocation".

Outside a function the keyword refers to linkage, inside it refers to allocation. All variables outside a function have static allocation implicitly. An unfortunate design perhaps, but there it is.