FINAL CLASS AND METHOD IN JAVA

Final class – A class which has final keyword in its definition is called final class and it cannot be extended. A class should be defined as final if we do not want to override all methods, our class is in subclass or if we do not want to extend outer class functionality

Final Method – A method which has final keyword in its definition is called final method. The rule for final keyword is it cannot be overridden in subclass, but it is inherited to subclass, and we can invoke it to execute its logic. If we do not want a subclass to override super class method and to ensure that all sub classes use the same super class method logic, then that method should be declared as final method.

Example –

class Example{

          void m1()

          {

                   System.out.println("in example m1");

          }

          final void m2()

          {

                   System.out.println("in example  m2");

          }

          void m3()

          {

                   System.out.println("in example m3");

          }

}

class Sample extends Example{

          void m1()

          {

                   System.out.println("in sample m1");

          }

          /* void m2() //CE{

                    System.out.println("in sample m2");

           */

}

class Tesr1 {

          public static void main(String[] args) {

                             Sample s = new Sample();

                             s.m1();

                             s.m2();

                             s.m3();

          }       

}

Output –

in sample m1

in example  m2

in example m3