Polymorphism.java

import java.io.*;
public class Polymorphism {
   static void m(Base1 b){
      b.add(8);
      b.print();
   }
   public static void main(String[] args) throws IOException {
      m(new Sub1());
      System.in.read();
   }
}

class Base1 {
   int i = 1;
   Base1(){
      add(1);
   }
   void add(int n){
      i+=n;
   }
   void print() {
      System.out.println(i);
   }   
}

class Sub1 extends Base1{
   Sub1(){
      add(2);
   }
   void add(int n){
      i+=n*2;
   }   
}

//Display 23, think why?