Simple java program using inheritance

So lets start of with a simple say basic java inheritance program. I hope the program would be self explanatory.

class Baseclass{  //this is a base class whose properties will be extended//
 int i;
 void show(){
 System.out.println(i); 
 }
}

class Subclass extends Baseclass{      //subclass inherits the properties of baseclass//
 int j;
 void display() {
  System.out.println(j);
 }
}

public class Demo{
 public static void main(String[] args) {
  Subclass object = new Subclass(); // creating object using Subclass // 
  object.i = 10;
  object.j = 20;
  object.show(); //calling a baseclass method using subclass object//
  object.display();  
 }
}