Encapsulation

Encapsulation in Java is a mechanism of wrapping the data (variables) and code acting on the data (methods) together as a single unit. In encapsulation, the variables of a class will be hidden from other classes, and can be accessed only through the methods of their current class. Therefore, it is also known as data hiding.

• Binding the data with its related functionalities known as encapsulation
• Here data means variables and functionalities means methods.
• So keeping the variable and related methods in one place.
• That place is "class". class is the base for encapsulation.
• Lets see example program on encapsulation, how the variables and methods defined in a class

/* File name : EncapTest.java */

public class EncapTest {

   private String name;

   private String idNum;

   private int age;

   public int getAge() {

      return age;

   }

   public String getName() {

      return name;

   }

   public String getIdNum() {

      return idNum;

   }

   public void setAge( int newAge) {

      age = newAge;

   }

   public void setName(String newName) {

      name = newName;

   }

   public void setIdNum( String newId) {

      idNum = newId;

   }

}

The variables of the EncapTest class can be accessed using the following program −

public class RunEncap {

   public static void main(String args[]) {

      EncapTest encap = new EncapTest();

      encap.setName("John");

      encap.setAge(20);

      encap.setIdNum("123");

      System.out.print("Name : " + encap.getName() + " Age : " + encap.getAge());

   }

}