Encapsulation

 Encapsulation is a fundamental concept in object-oriented programming (OOP) that helps to organize and protect data by hiding its implementation details. It is one of the four key principles of OOP, alongside abstraction, inheritance, and polymorphism. In Java, encapsulation is implemented through classes, access modifiers, and getter/setter methods. In this article, we'll explore what encapsulation is and how it works in Java.

What is Encapsulation?

Encapsulation is the process of hiding implementation details and organizing data into a logical unit. In Java, encapsulation is achieved through classes, which encapsulate data and methods into a single unit. The data is hidden from the outside world, and access to it is restricted through access modifiers.

Access Modifiers

Access modifiers are keywords that determine the level of access to a class member (field or method). There are four access modifiers in Java:

public: The member can be accessed from anywhere.

private: The member can only be accessed from within the same class.

protected: The member can be accessed from within the same class, subclasses, and same package.

default (no keyword): The member can be accessed from within the same package only.

By using access modifiers, we can control the visibility and accessibility of class members, and ensure that data is accessed and modified only in the intended way.

Getter/Setter Methods

Getter and setter methods are used to access and modify private data members. They provide an interface to the outside world, while still maintaining encapsulation.

A getter method is used to retrieve the value of a private data member, while a setter method is used to set the value of a private data member. Both getter and setter methods are public and can be accessed from outside the class.

Here is an example of a class with encapsulated data and getter/setter methods:

In this example, the Person class has two private data members: name and age. Getter and setter methods are provided for each data member, allowing outside classes to access and modify the data, while still maintaining encapsulation.

Encapsulation in Action

Let's take a look at an example to see how encapsulation works in Java:

In this example, we have a BankAccount class that encapsulates the account number and balance data. The class provides getter and setter methods for the balance data, as well as methods to deposit