Final Keyword

Final variables:

• Any variable declare along with final modifier then those variables treated as final variable.
•  if we declare final variables along with static will became constants.
• while declaring itself we need to assign these final variables.
• final int a;

Example program: 

   class finalvariabledemo{

   final int a=10;
    public static void main(String args[]){
    finalvariabledemo obj= new finalvariabledemo();
    //obj.a=24;  this will rise compile time error
}
}

Output:

Compile time Error.

Final Method:

• If you declare method as final that method also known as final methods.Final methods are not overridden.means we can't overridden that method in anyway.
• public final void add(){
   }
   public class A{
   void add(){
   //Can't override
   }
   }

Final Class:

• If you declare class is final that class is also known as final classes.Final classes are not extended.means we can't extends that class in anyway.
• public final class indhu{
   }
   public class classNotAllowed extends indhu {...} //not allowed