What ia abstract variable in java

It's possible to define variables of an abstract class.

However, because the abstract class itself cannot be instantiated, you can only assign references to 'concrete' derived class objects to such variables.

For example:

import java.io.*;

class AbstractDemo

{

public static void main(String[] args)

{

Animal animal = new Bear();

animal.MakeNoise(); // Growl!

}

abstract class Animal

{

public abstract void MakeNoise();

}

class Bear extends Animal

{

public void MakeNoise()

{

System.out.println("Growl!");

}