How to use a object created in a subclass of a abstract class, in the abstract class

Question

I have created a plane seat booking system via a brief that was provided by my university for a assignment. I am running into one main problem that I just can not figure out.

The brief states that the abstract class must have one abstract method and about 4 public methods. In both of the subclasses of the abstract class we have to initialize the array of objects (all plain seats). However, once they are initialized I do not know how I can send them back to the abstract class (which has a method that checks for unbooked plane seats, this is where I need the initialized seat object)

ArrayIndexOutOfBounds on a object that should be in bounds

The above link contains every single one of the classes and their code, I had a previous error which someone helped me fix and just thought it would be easier to link the full files here.

I just want to use the initialized array of objects (seats) created in a subclass of a abstract class, in the abstract class.

All input is greatly appreciated!

Answer 1

In the abstract class method(where you want to use the initialized array), you can just assume the array is already initialized. However, in the subclass, you cannot have another "Seat[][] newSeats;". So, just delete that in all sub-classes.

A quick example is as following,

//This will print 6 to the std output
public class HelloWorld{

     public static void main(String []args){
        Child test = new Child();
        System.out.println(test.getArrFirst());
     }


     public static abstract class Parent{
        int[] abc;

        public int getArrFirst(){
            return abc[1];
        }
     }

     public static class Child extends Parent{

         public Child(){
             abc = new int[10];
             abc[1] = 6;
         }
     }
}

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