I came from the java world so I don't understand how it works

Question

suppose I have a class A with a attribute of type B (another class)

please take the idea, sorry for errors

class B {}

class A {
public:
B b;
}

what happens with B if I have
const A a;

Answer 1

The object is still mutable internally. Same as with final in Java actually.

Answer 2

what I mean is what happens to B
is it constant too?
thanks!

Answer 3

so if I understand well "the pointer" of the variable can't change
thanks!