static variable in subclass Java

Question

I need to have a static variable that is not related to an object, but to the class itself. However, the variable must also not be related to the parent class, or all other sub-classes that extends the same parent class.

let's say:

    class Army{
      static int attack = 0;
    }

    class Warrior extends Army{
      public Warrior(){ 
        attack = 50;   // every Warrior object will have attack value of 50
      }
    }

    class Archer extends Army{
       public Archer(){ 
         attack = 75; // every Archer object will have attack value of 75
       }
    }

Is it possible? Or do I need to declare the static variable in each subclass? I've tried and when I tried to access the static variable, the static variable's value ended up the same for every class.

Answer 1

Your current code won't do what you want, since there is only one attack variable in Army class, and it can have only one value.

You could have a method in Army that returns a default value :

public int getAttack()
{
    return 10;
}

Then you can override this method in your sub classes :

class Warrior extends Army
{
    ...
    @Override
    public int getAttack()
    {
        return 50;
    }
    ...
}

class Archer extends Army
{
    ...
    @Override
    public int getAttack()
    {
        return 75;
    }
    ...
}

Even though getAttack() is not a variable, and it's not static, it still fulfills your requirements - each sub-class can have a different value shared by all instances of that sub-class.

Answer 2

No it's not possible. The parent class knows nothing about static or non-static members in it's subclasses.

However the code you've posted tells me you want to override a static variable. It's not possible either, only non-static methods can be overriden (if they have the appropriate access level).