Question

What is the proper way to modify a field of outer class? When trying to change from inner static class the value of Artifact it gives an error. There is need to iterate over array list which contains objects of type Artifact; and be able to display for each Artifact (whether it is Coin or Goblet) the value.

 public class Artifact {
        public int value = 0;

        public static class  Goblet extends Artifact{
            value = 5; // Syntax error on token "value", VariableDeclaratorId expected after this token
        }
        public static class Coin extends Artifact{
            value = 10;
        }

    }

Answer 1

You can’t have a statement value = xxx; outside of either a method or a block.

This would work:

public class Artifact {

    public static void main(String[] args) {
        Artifact goblet = new Goblet();
        Artifact coin = new Coin();

        System.out.println(goblet.value); //prints 5
        System.out.println(coin.value); //prints 10
    }

    public int value = 0;

    public static class Goblet extends Artifact {

        {value  = 5;}
    }

    public static class Coin extends Artifact {

        {value  = 10;}
    }
}