Java Object

Instanceof operator can be used for determining that dog is an animal & Mammal is an animal.
interface Animal{}

Java Code:

class Mammal implements Animal{}

class Dog extends Mammal{
   public static void main(String args[]){

      Mammal m = new Mammal();
      Dog d = new Dog();

      System.out.println(m instanceof Animal);
      System.out.println(d instanceof Mammal);
      System.out.println(d instanceof Animal);
   }
}

Following result will be produced:

true
true
true