Access Specifiers in Java

Access Specifiers in Java

1. Four Levels (beginner ladder!)

Who can see? private (me!) → default (package!) → protected (package + kids!) → public (world!). Default = NO word (package-private!).

2. Master Table (memorize — exam garanateed!)

public class Demo {
    private int a;    // self only!
    int b;            // default (package!)
    protected int c;  // package + children anywhere!
    public int d;     // everyone!
}

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

3. Class-Level Rule (trap!)

Top-level class: ONLY public or default! (private/protected class = ERROR! Inner classes CAN use all four!).

// private class A {} // ERROR! (top-level!)
public class A {}     // ok (file A.java!)
class B {}            // ok (package-private!)

4. Best Practice (viva line!)

Fields private + getters/setters (encapsulation!). Methods public (API) / private (helper). Library hooks protected.

5. Exam Points

• Four-level table + program — 7 marks, very frequent.
• Default vs protected + class rule — 5 marks, favourite traps.