Abstract class members

[Krishna Mir]

What is the use of having private member variables of an Abstract class when all its methods are also abstract?

ex:

abstract class Car
{
private double price;
private String model;

public abstract void goFast();
public abstract void goUpHill();
}

[Thomas De Vos]

There is no sense in defining these kind private variables in an abstract class. They are not visible.

[Salil S Fadnavis]

  public class myAbstract extends myAbs{
 
public static void main(String argv[]){
myAbstract ma = new myAbstract();
ma.display();
}
 
}
 
abstract class myAbs{
private int i = 11;
private int j = 10;
 
public void display(){
System.out.println("i is:" + i);
System.out.println("j is:" + j);
}
}  

this code will give a output of i is 11 and j is 10. So you could use them as constants??? . Dont see any real use of them.

[Thomas De Vos]

Salil,

The original question was when all methods are abstract and in your example you are not using the variables directly from outside the abstract class.

[Salil Fadnavis]

But thats true for all private variables.
Can anyone please shed light when we would use private variables in abstract classes, or is it just one of those things u can do in Java but never use in real life.

[santosh kothapalli]

Salil what u should rememeber is abstrat class does not stop you from writing methods that have implementation, so private variables can be accessed by those methods.In reality it happens that only few methods are absract that need to be implemented as the way u want and not all methods.
If u declare variables as wether public,private or whatever and if u dont use them it make little sense.

i think i cleared ur doubt.

santosh.

[vandu matcha]

when all the methods are abstract...then declaring private member variables is of no use then.....

[Thomas De Vos]

Originally posted by vandu matcha:
when all the methods are abstract...then declaring private member variables is of no use then.....

Absolutely