Type casting not clear

Question

Class Animal{

public void makeSound(){
..
}

}

class Dog extends Animal{

public void makeSound(){
..
}

public void eatFood(){
..
}

}

Now let’s make an analogy with data types

Animal=> int // since it contains only one method makeSound() thus small size

Dog => double // since it contains two methods makeSound() and eatFood() thus big size

Then why is Animal a = new Dog() // upcasting implicit shouldn’t it be explicit since there is loss of data

Answer 1

What loss of data?
What is happening is that an Animal object is created that will have /*all of dog methods,*/ so yes it is upcasting
Edit: *only the dog methods that override Animal methods

Answer 2

@Laxman, the animal object will have the eatFood() method

Answer 3

@Laxman, my bad...The animal object will only have the makeSound() method of the dog class, its own is overrided

Answer 4

you don't have loss of data because class Dog have all features off class animal and some extra features

Answer 5

Since a is of type Animal and new Dog() will create an object of type Dog and assign to a

So isn’t there a loss of data as a can hold only one method i.e makeSound()

Sorry I may be asking a very basic question but I am not convinced

Answer 6

@Yerucham The Animal object will not have the eatFood() method it will give error :(