OnJava8-Examples/arrays/CollectionComparison.java

// arrays/CollectionComparison.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.
import java.util.*;
import onjava.*;
import static onjava.ArrayShow.*;

class BerylliumSphere {
  private static long counter;
  private final long id = counter++;
  @Override public String toString() {
    return "Sphere " + id;
  }
}

public class CollectionComparison {
  public static void main(String[] args) {
    BerylliumSphere[] spheres =
      new BerylliumSphere[10];
    for(int i = 0; i < 5; i++)
      spheres[i] = new BerylliumSphere();
    show(spheres);
    System.out.println(spheres[4]);

    List<BerylliumSphere> sphereList = Suppliers.create(
      ArrayList::new, BerylliumSphere::new, 5);
    System.out.println(sphereList);
    System.out.println(sphereList.get(4));

    int[] integers = { 0, 1, 2, 3, 4, 5 };
    show(integers);
    System.out.println(integers[4]);

    List<Integer> 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
*/