Protected Specifier

Protected Specifier

1. Where Protected Sits (beginner)

Access ladder (strict → open): private (self only!) → default (package!) → protected (package + children anywhere!) → public (world!). Protected = "family + neighbours!"

2. Table + Package Proof (exam diagram!)

package zoo;
public class Animal { protected String name = "Leo"; } // protected!
// same package (zoo): ANY class sees name! (like default!)
// other package + child: sees via extends!
package city;
import zoo.Animal;
class Dog extends Animal {
    void show() { System.out.println(name); } // OK! (child anywhere!)
}
class Vet {
    // System.out.println(new Dog().name); // ERROR! (not child, different package!)
}

Modifier	Same class	Same package	Child (other pkg)	World
private	Yes	No	No	No
default	Yes	Yes	No	No
protected	Yes	Yes	Yes (via extends!)	No
public	Yes	Yes	Yes	Yes

3. Traps

• Default (no word!) ≠ protected: default blocks outside-package children!
• Protected field via PARENT ref in child: Animal a = new Animal(); a.name from other package = ERROR (must via this/child ref!).
• Exam asks "which modifier for library + subclass reuse?" → protected!

4. Exam Points

• Four-level table + child-outside proof — 5-7 marks, very frequent.
• Protected vs default — 3-5 marks, favourite distinction.