static constant members for array size

Question

MyClass.h

class MyClass
{
public:

static const int cTotalCars;

private:

int m_Cars[cTotalCars];
};

MyClass.cpp

Answer 1

Static const members of simple type are a exception to that rule, so you latter code is correct.

This exception is a fairly modern one (from C++98, but not implemented by every compiler until a few years later) so many old-fashioned teachers are not yet aware of it. They prefer the idiom:

class MyClass
{
public:
   enum { cTotalCars = 5 };

private:
    int m_Cars[cTotalCars];
};

That behaves exactly the same, but makes little sense nowadays.