Question

If I have code like this:

int e;
int* f;

int main() {
    int a, b, c;
    int* d;
}

Where in memory are these variables stored?
And, what’s the problem with defining global variables (out of a function, like main in this case)?

Answer 1

a,b,c and d will exist on the stack. If you were to create an instance of an int (with malloc or new), that would go on the heap – but the pointer called ‘d’ would still exist on the stack.

e and f are allocated space in the memory space of the app, in the so-called ‘Data segment’ – see:

http://en.wikipedia.org/wiki/Data_segment

You also asked about stack size: that’s configured by the compiler, see here:

http://msdn.microsoft.com/en-us/library/tdkhxaks(VS.71).aspx