What is Encapsulation?

Encapsulation is one of the fundamental principles of Object-Oriented Programming (OOP). It refers to wrapping data (fields) and methods (functions) that operate on the data into a single unit (class) — and restricting direct access to that data.

Key Points:

• Data is hidden from outside classes.
• Access to data is provided through getters and setters.
• Improves security, modularity, and maintainability.

How to Achieve Encapsulation in Java:

1. Make fields private.
2. Provide public getter and setter methods to access and update the values.

Example: Encapsulation in Java

class Employee {
    // Step 1: private fields
    private String name;
    private int salary;

    // Step 2: public getter and setter methods
    public String getName() {
        return name;
    }

    public void setName(String newName) {
        name = newName;
    }

    public int getSalary() {
        return salary;
    }

    public void setSalary(int newSalary) {
        if(newSalary > 0) {
            salary = newSalary;
        } else {
            System.out.println("Salary must be positive!");
        }
    }
}

public class Main {
    public static void main(String[] args) {
        Employee emp = new Employee();

        emp.setName("John Doe");
        emp.setSalary(50000);

        System.out.println("Name: " + emp.getName());
        System.out.println("Salary: ₹" + emp.getSalary());
    }
}

Output:

Name: John Doe
Salary: ₹50000

Why Use Encapsulation?

Real-Life Analogy:

Think of ATM machines:

• You don’t access the internal logic.
• You interact through buttons (methods).
• Your PIN and balance (data) are encapsulated and secure.

Summary