为什么受保护的成员被放置在不同包中的类的子类的子类访问

Question

Why this code runs fine??

package certification;
public class Parent {
    protected int x = 9; // protected access
    protected void z(){System.out.println(5);}
}


package other;
import certification.Parent;
class C extends Parent{}
public class Child extends C {
    public void testIt() {
        System.out.println("x is " + x);
        this.z();
    }

}

import other.Child;
class Test extends Child{
    public static void main(String args[]){
        new Child().testIt();
    }
}

This gives output:

x is 9

5

But how can subclass(Child) of subclass(C) can access protected member of class Parent.

Answer 1

In your example class Child extends C and class C extends Parent. This means Child is a subclass of Parent. Protected fields are visible both to all subclasses and to classes in the same package. https://docs.oracle.com/javase/tutorial/java/javaOO/accesscontrol.html