Understanding java's protected modifier

Question

I have a class called A in package1 and another class called C in package2. Class C extends class A.

A has an instance variable which is declared like this:

<

Answer 1

Protected means :

a)This member will be accessible to all classes in same package through A object’s reference.

b) For different package, this will be accessible only inside Subclasses of A say B and the reference used can be of B instance or of any subclass of B.

Let's take an example:

Let A be parent class in some package say com.ex1 Let B ,C be classes in different package w.r.t to A say com.ex2 . Also, B extends A and C extends B. We will see how we can use protected field of A inside B (a subclass of A)

A's code:

public class A {
    protected int a = 10;
}

B's code:

public class B extends A {


    public void printUsingInheritance() {
        // Using this
        System.out.println(this.a);
    }


    public void printUsingInstantiation() {
        // Using instance of B
        B b = new B();
        System.out.println(b.a);

        // Using instance of C as C is subclass of B
        C c = new C();
        System.out.println(c.a);


        A a = new A();
        System.out.println(a.a); // Compilation error as A is not subclass of B
    }
}

C's code:

public class C extends B {

}

For protected Static :

Same rules apply except that in b) now it is accessible in any subclass of A by A's class reference. Reference