TestLinkedList.java

import java.util.Iterator;

public class TestLinkedList {
  
  public static void test() {
    LinkedList<String> l = new LinkedList<>();

    System.out.println(l.isEmpty() ? "The list is empty." : "The list is not empty.");
    System.out.println(l);
    System.out.println();

    l.add(0, "John");
    l.add(0, "Elvis");
    l.add(0, "Sydney");
    l.add("Judy");
    l.add(4, "Paul");
    System.out.println(l);
    System.out.println();

    System.out.println(l.isEmpty() ? "The list is empty." : "The list is not empty.");
    System.out.println();

    LinkedList<String> l2 = new LinkedList<String>();
    l2.add("Sydney");
    l2.add("Elvis");
    l2.add("John");
    l2.add("Judy");
    System.out.println("l.equals(l2) is " + l.equals(l2));
    System.out.println();

    l.add("Mick");
    System.out.println(l);
    System.out.println();

    l.add(0, "Curly");
    l.add(3, "Larry");
    l.add(2, "Diana");

    System.out.println(l);
    System.out.println();

    l.add(0, "Moe");
    System.out.println("Replacing " + l.set(4, "Bruce") + " with Bruce");
    System.out.println(l);
    System.out.println("size = " + l.size());
    System.out.println("index of \"Curly\" = " + l.indexOf("Curly"));
    System.out.println("index of \"Larry\" = " + l.indexOf("Larry"));
    System.out.println("index of \"Moe\" = " + l.indexOf("Moe"));
    System.out.println("index of \"Mick\" = " + l.indexOf("Mick"));
    System.out.println();

    // remove first and last elements plus an element in the middle
    System.out.println("Removing " + l.remove(0));
    System.out.println("Removing " + l.remove(l.size() - 1));
    System.out.println("Removing " + l.remove(3));
    System.out.println(l);
    System.out.println("size = " + l.size());
    System.out.println("index of \"Diana\" = " + l.indexOf("Diana"));
    System.out.println("index of \"Bruce\" = " + l.indexOf("Bruce"));
    System.out.println();

    for (int i = 1; i <= 2; ++i)
      System.out.println("Removing " + l.remove(0));
    System.out.println(l);
    System.out.println();

    l.add(1, "Angela");
    l.add(l.size(), "Robert");
    System.out.println(l);
    System.out.println("size = " + l.size());
    System.out.println();

    // add a null data value and see if the list can be printed
    l.add(3, null);
    System.out.println(l);
    System.out.println("size = " + l.size());
    System.out.println();

    try {
      Iterator<String> iter = l.iterator();
      while (iter.hasNext()) {
        iter.next();
      }
      iter.next(); // force an exception
    } catch (Exception e) {
      System.out.println("Exception information to follow:");
      e.printStackTrace(System.out);
    }
    System.out.println();

    l.clear();
    System.out.println("The list has been cleared.");
    System.out.println(l.isEmpty() ? "The list is empty." : "The list is not empty.");
    System.out.println("index of \"Larry\" = " + l.indexOf("Larry"));
    System.out.println();

    try {
      l.remove(0); // should throw an exception
    } catch (Exception e) {
      System.out.println("Exception information to follow:");
      e.printStackTrace(System.out);
    }
  }
}