Encapsulation In Java

• What is Encapsulation
• Why we need Encapsulation in Java?
• Benefits of Encapsulation
• Encapsulation Example

What is Encapsulation in Java?

Encapsulation refers to the binding of the data member and member function (methods) in a single unit. In other words, we can say that Encapsulation is made a protective shield by which it prevents the data from the outer side of the shield. Because of Encapsulation, the variables and data members (methods) of a class is hidden from other classes and can be accessed only through the member function of the same class where they are declared. Therefore, it is also known as data hiding.

Important Points of Encapsulation:

• In Encapsulation, the data members (Variables) and Methods (functions) of a class are hidden from the classes but can be accessed only through the member functions of own class in which they are declared.
• The data of a class is hidden from other classes, so it is also known as data-hiding.
• We can achieve the encapsulation by declaring the variables as private and writing public methods to set and get the values of the variables.

Example Of Encapsulation:

• When we are writing a java program, that itself is an example of encapsulation. Because when we write a class that binds the variables and methods in a single unit and hides the complexity of class from other classes.
• Another Good example of encapsulation is a capsule because a capsule also encapsulate different medicine under a capsule

Simple Program to Understand Encapsulation:

Add the Program

Program 1: (Base Class)

// Java program to demonstrate encapsulation
public class Encapsulate
{
   // private variables declared
   // these can only be accessed by
   // public methods of class
   private String geekName;
   private int geekRoll;
   private int geekAge;

   // get method for age to access
   // private variable geekAge
   public int getAge()
   {
      return geekAge;
   }

   // get method for name to access
   // private variable geekName
   public String getName()
   {
      return geekName;
   }

   // get method for roll to access
   // private variable geekRoll
   public int getRoll()
   {
      return geekRoll;
   }

   // set method for age to access
   // private variable geekage
   public void setAge( int newAge)
   {
      geekAge = newAge;
   }

   // set method for name to access
   // private variable geekName
   public void setName(String newName)
   {
      geekName = newName;
   }

   // set method for roll to access
   // private variable geekRoll
   public void setRoll( int newRoll)
   {
      geekRoll = newRoll;
   }
}

Extended Class: Child Class

public class TestEncapsulation
{
   public static void main (String[] args)
   {
      Encapsulate obj = new Encapsulate();

      // setting values of the variables
      obj.setName("Harsh");
      obj.setAge(19);
      obj.setRoll(51);

      // Displaying values of the variables
      System.out.println("Geek's name: " + obj.getName());
      System.out.println("Geek's age: " + obj.getAge());
      System.out.println("Geek's roll: " + obj.getRoll());

      // Direct access of geekRoll is not possible
      // due to encapsulation
      // System.out.println("Geek's roll: " + obj.geekName);
   }
}

Advantages of Encapsulation

Data Hiding: During this process, the user doesn’t have any idea about the inner implementation of the class, like how the values are stored inside a variable. The user only aware that they are passing a value to a setter method, and the value is initialized in that variable.

Reusability: The encapsulated code is more flexible and easy to change with the new requirements.

• It Prevents other classes to access the private fields.
• It also allows us to modify the implemented code without breaking other’s code. Those have already implemented the code.
• It improved the maintainability of the program and application.
• If you require to define the fields as read-only, then you can do that by similarly defining only getter methods if you want the fields as only write-only, then you can also do that by only mentioning the setter method.

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