🥁Modifiers

Modifier	Description	Example Code
Public	Accessible from any class or package	public class ExampleClass { }
Private	Accessible only within the same class	private int exampleVariable;
Protected	Accessible within the same class and its subclasses	protected void exampleMethod() { }
Static	Belongs to the class rather than a specific instance	public static void exampleMethod() { }
Final	Cannot be modified once initialized	private final int EXAMPLE_CONSTANT = 10;
Abstract	Cannot be instantiated and must be extended	public abstract class ExampleAbstractClass { }

Rules for Java Modifiers

Java modifiers allow controlling access to classes, variables, methods, etc. Here are some key rules:

Access Modifiers

• public - Accessible from any class

• protected - Accessible within package and subclasses

• default (no modifier) - Accessible within the package only

• private - Accessible only within the class

For example:

public class Main {

  private String name; //only accessible within Main
  
  void print() { //default access
    
  }

}

Non-Access Modifiers

• static - Belongs to the class rather than an instance

• final - Cannot be inherited or modified

• abstract - Method signature without implementation

• synchronized - One thread access at a time

For example:

public abstract class Parent {

  public static final int VALUE = 10;
  
  protected synchronized void print() {
    //...
  }

}

Rules

• Only one public class per file

• Public class must match filename

• Interface methods are implicitly public

• Variables are default access if no modifier

So modifiers allow flexible access control in Java.

Java Access Levels

• private - Access only within class 👪

• default - Access within package 📦

• protected - Access within package + subclasses outside package 👪👫

• public - Access everywhere 🌎

Access Summary

Modifier	Class	Package	Subclass	Outside
private	Y	N	N	N
default	Y	Y	N	N
protected	Y	Y	Y	N
public	Y	Y	Y	Y

Key Points:

• private is most restrictive, public is most open

• Omitting access modifier defaults to package-level access

• protected gives subclass access outside package

• Understanding access modifiers is key to encapsulation