Access Control and Inheritance

[Lucas Toledo]

Dear forum,
I understand that default instance variables can only be accessed in same package, and that protected instance variables can be accessed outside the package only through inheritance.
However, II have the following code:

package com;
public class Parent {
	private int a=0;
	int b=1;
	protected int c=2;
	public int d=3;
}

and the following test programs in a different package:

package org;
import com.*;
public class Child extends Parent {
        public static void main(String[] args) {
                Child c = new Child();
                System.out.println("child inherited default CANNOT be accessed ");
                System.out.println("child inherited protected " + c.c);
                System.out.println("child inherited public " + c.d);
        }
}

AND I also have the following program:

package org;
import com.*;
class TestAccess{
	public static void main(String[] args){
		Child c = new Child();
		System.out.println("child inherited default CANNOT be accessed");
                System.out.println("child inherited protected CANNOT be accessed");
                System.out.println("child inherited public " + c.d);
	}
}

My question is, why is it that Child's inherited protected variable c CAN be accessed from Child.main but not from TestAccess.main? it is in the same package, after all.
Thanks in advance,

[saloni jhanwar]

Because you are trying to access a protected variable which is not owned by child main.It is inherited from other class in other package.If it is owned by child itself then sure you can access it.So if you want access it in TestAccess class then you have to inherit child main because that protected variable will be available for only child classes of child main through inheritance only.

[John Jai]

This old thread also describes the protected access modifier using the Object class' clone() method.

[dennis deems]

Lucas Toledo wrote:My question is, why is it that Child's inherited protected variable c CAN be accessed from Child.main but not from TestAccess.main? it is in the same package, after all.

TestAccess is in the same package as Child, but not in the same package as Parent, and that's the relationship that matters. The variables with protected access in the class com.Parent are visible to other classes in the package com. They are also visible within classes in other packages that extend Parent. They are NOT visible within classes in other packages that DO NOT extend Parent. Merely because org.Child extends Parent does not open visibility of Parent.c to any other class in the package org. That is not how it works.