Encapsulation in Java

What is Encapsulation:

Encapsulation is the process of binding data (variables) and methods into a single unit called a class. It is used to protect data from unauthorized access.

Encapsulation is achieved by:

1. Declaring variables as private.
2. Providing public getter and setter methods to access and update the data.

Why Use Encapsulation:

• Provides data security.
• Prevents unauthorized access.
• Improves maintainability.
• Provides better control over data.
• Follows the principle of data hiding.

class Student {

    private String name;

    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }
}

public class Main {

    public static void main(String[] args) {

        Student s = new Student();

        s.setName("Bala");

        System.out.println(s.getName());
    }
}

Output:

Bala

Access Modifiers in Java

Access modifiers control the visibility and accessibility of classes, variables, methods, and constructors.

There are four types of access modifiers:

1. Public
2. Private
3. Protected

4. Default

5. Public

A public member can be accessed from anywhere in the program

public class Demo {

    public int age = 22;
}

Access:

• Same class
• Same package
• Different package
• Subclass

1. Private

A private member can be accessed only within the same class.

class Demo {

    private int age = 22;
}

Access:

• Same class
• Same package
• Different package
• Subclass

1. Protected

A protected member can be accessed within the same package and by subclasses.

class Demo {

    protected int age = 22;
}

Access:

• Same class
• Same package
• Different package
• Subclass

1. Default

When no access modifier is specified, it becomes default access.

class Demo {

    int age = 22;
}

Access:

• Same class
• Same package
• Different package
• Subclass (different package)