Question

I am getting into c++ from a heavy java background.

How do you have constants associated with a class?
If it was Java it would be something like

public class Example{
    public static final int CONSTANT = 0;
}

public static void main (String[] args){
    System.out.println(Example.CONSTANT);
}

And the result would be just 0.

In c++ I have figured so far:

class Example{
    const int LEVEL_INF;
}

Is this correct?
Even by ISO 98?

Answer 1

class Example{
    const int LEVEL_INF;
};

is not per class, but per instance. You need to make it static:

class Example{
    static const int LEVEL_INF;
};

The advantage of static const integral types is that you can initialize them inside the class, not necessarily outside:

class Example{
    static const int LEVEL_INF = 1337;
};

Also, add public if you want public access to it.

EDIT: As per @ildjarn’s suggestion, to initialize it outside the class:

//header.h
class Example{
    static const int LEVEL_INF;
};

//implementation.cpp

const int Example::LEVEL_INF = 1337;