Question

How would you declare a static variable in Super and instantiate it in subclass

Example

class A
{
  static Queue<String> myArray;

  public void doStuff()
  {
     myArray.add(someMethod.getStuff());
  } 

}
class B extends A
{
  myArray = new LinkedList<String>();

}

class C extends A
{
  myArray = new LinkedList<String>();

}

Obviously this doesnt work. But how would you go about declaring a variable; then doing some common functionality with the variable in the super class; Then making sure each subclass gets it own static LinkedList?

Answer 1

Since, you have subclass-specific properties to manipulate, you can’t do it in the superclass, and it is not logical to do it anyways. As was already mentioned, you can do something like this:

abstract class A {
      public abstract void doStuff();       
    }

class B extends A    {
  static List<String>myArray = new LinkedList<String>();

  public abstract void doStuff() {
      // do B stuff
  }

}

class C extends A  {
  static List<String>myArray = new LinkedList<String>();
  public abstract void doStuff() {
      // do C stuff
  }

}