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Private vs Protected in Java

Updated: Dec 16, 2023


Private vs Protected in Java

Private vs. Protected in Java: Understanding Access Modifiers

Java, as one of the most popular programming languages, offers a range of access modifiers to control the visibility and accessibility of class members (fields, methods, and inner classes). Two frequently used access modifiers are private and protected. In this blog post, we'll dive deep into Private vs Protected in Java and provide real-world examples to illustrate their usage. Access Modifiers Overview

Access modifiers in Java define the visibility of class members. They help encapsulate the internal state of a class and control how other classes or sub classes can interact with it. Java offers four main access modifiers:


Private (private): The most restrictive access modifier. Members declared as private are only accessible within the same class. They are invisible to other classes, including sub classes.


Default (No Modifier): If no access modifier is specified, the default access modifier is applied. Members with default access are visible within the same package but not outside it.


Protected (protected): Members declared as protected are accessible within the same package and by sub classes, whether they are in the same package or not.


Public (public): The least restrictive access modifier. Members declared as public are accessible from any class, anywhere.


Core Java Programming

Java Back-End Development


Private Access Modifier

The private access modifier is commonly used to hide the internal implementation details of a class. This is particularly useful when you want to enforce encapsulation, ensuring that no external class can directly access or modify the private members of a class.

Real-World Example: Encapsulation class BankAccount {

private double balance;


public void deposit(double amount) {

if (amount > 0) {

balance += amount;

}

}


public double getBalance() {

return balance;

}

}

In this example, the balance field is declared as private. It can only be accessed and modified through the deposit and getBalance methods, ensuring that the balance remains valid and protected from external interference.

Protected Access Modifier

The protected access modifier provides a level of visibility between private and public. It allows subclass access and access within the same package, which is useful for creating a more flexible class hierarchy.

Real-World Example: Inheritance package com.example;

class Animal {

protected void makeSound() {

System.out.println("Animal makes a sound");

}

}


class Dog extends Animal {

@Override

protected void makeSound() {

System.out.println("Dog barks");

}

}


public class Main {

public static void main(String[] args) {

Dog myDog = new Dog();

myDog.makeSound(); // Output: Dog barks

}

}

In this example, the makeSound method in the Animal class is declared as protected. This allows the Dog subclass to override and access it while still restricting access from classes outside the package.


When to Use Private vs. Protected

The choice between private vs protected in Java (access modifiers) depends on your design goals:


Use private when you want to hide implementation details and ensure strict encapsulation. This is common for fields and methods that should not be accessed directly by external classes.


Use protected when you want to allow sub classes to access or override a member while maintaining some level of control over its visibility within the package.


Remember that access modifiers are essential for maintaining the integrity of your code and ensuring that classes are used in the intended way.


In summary, understanding the differences between private and protected access modifiers in Java is crucial for creating well-structured and maintainable code. Use them wisely to strike the right balance between encapsulation and flexibility in your Java programs.

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