// arrays/ContainerComparison.java // ©2016 MindView LLC: see Copyright.txt // We make no guarantees that this code is fit for any purpose. // Visit http://mindviewinc.com/Books/OnJava/ for more book information. import java.util.*; class BerylliumSphere { private static long counter; private final long id = counter++; @Override public String toString() { return "Sphere " + id; } } public class ContainerComparison { public static void main(String[] args) { BerylliumSphere[] spheres = new BerylliumSphere[10]; for(int i = 0; i < 5; i++) spheres[i] = new BerylliumSphere(); System.out.println(Arrays.toString(spheres)); System.out.println(spheres[4]); List sphereList= new ArrayList<>(); for(int i = 0; i < 5; i++) sphereList.add(new BerylliumSphere()); System.out.println(sphereList); System.out.println(sphereList.get(4)); int[] integers = { 0, 1, 2, 3, 4, 5 }; System.out.println(Arrays.toString(integers)); System.out.println(integers[4]); List intList = new ArrayList<>( Arrays.asList(0, 1, 2, 3, 4, 5)); intList.add(97); System.out.println(intList); System.out.println(intList.get(4)); } } /* Output: [Sphere 0, Sphere 1, Sphere 2, Sphere 3, Sphere 4, null, null, null, null, null] Sphere 4 [Sphere 5, Sphere 6, Sphere 7, Sphere 8, Sphere 9] Sphere 9 [0, 1, 2, 3, 4, 5] 4 [0, 1, 2, 3, 4, 5, 97] 4 */