LR Creations

  Encapsulation Encapsulation  is one of the four fundamental OOP concepts. The other three are inheritance, polymorphism, and abstraction. 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 . To achieve encapsulation in Java − 1.) Declare the variables of a class as private. 2.) Provide public setter and getter methods to modify and view the variables values 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 ;

Interfaces Another way to achieve Abstraction  in Java, is with interfaces. Is equivalent to a Class. But not a class. interface FirstInterface { public void myMethod ( ) ; // interface method } interface SecondInterface { public void myOtherMethod ( ) ; // interface method } class DemoClass implements FirstInterface , SecondInterface { public void myMethod ( ) { System . out . println ( "Some text.." ) ; } public void myOtherMethod ( ) { System . out . println ( "Some other text..." ) ; } } class Main { public static void main ( String [ ] args ) { DemoClass myObj = new DemoClass ( ) ; myObj . myMethod ( ) ; myObj . myOtherMethod ( ) ; } } Like  abstract classes , interfaces  cannot  be used to create objects (in the example above, it is not possible to create an "Animal" object in the MyMainClass) Interface methods do not have a body - the body is provided by the &q