// generics/CovariantArrays.java // (c)2021 MindView LLC: see Copyright.txt // We make no guarantees that this code is fit for any purpose. // Visit http://OnJava8.com for more book information. class Fruit {} class Apple extends Fruit {} class Jonathan extends Apple {} class Orange extends Fruit {} public class CovariantArrays { public static void main(String[] args) { Fruit[] fruit = new Apple[10]; fruit[0] = new Apple(); // OK fruit[1] = new Jonathan(); // OK // Runtime type is Apple[], not Fruit[] or Orange[]: try { // Compiler allows you to add Fruit: fruit[0] = new Fruit(); // ArrayStoreException } catch(Exception e) { System.out.println(e); } try { // Compiler allows you to add Oranges: fruit[0] = new Orange(); // ArrayStoreException } catch(Exception e) { System.out.println(e); } } } /* Output: java.lang.ArrayStoreException: Fruit java.lang.ArrayStoreException: Orange */