Difference between ArrayList class and LinkedList class

Question

I would like to ask what is the difference between the ArrayList class and the LinkedList class? If I use ArrayList class can I have a fixed size?
Thank you for your answers.

Answer 1

I often use LinkedList when I need a FIFO. When all you're doing is adding to the end of a list and removing the first element, it is definitely faster. Here's a quick SSCCE I wrote up to demonstrate:import java.util.*;
public class ListTest {
   public static void main(String[] args) {
      LinkedList<Integer> linked = new LinkedList<Integer>();
      ArrayList<Integer> array = new ArrayList<Integer>();
      Integer[] values = new Integer[2500000];
      for (int i = 0; i < values.length; i++) {
         values[i] = new Integer(i);
      Random rand = new Random();
      boolean[] randDir = new boolean[values.length];
      for (int i = 0; i < randDir.length; i++) {
         randDir[i] = rand.nextBoolean();
      long startTime, endTime;
      startTime = System.currentTimeMillis();
      for (int i = 0; i < values.length; i++) {
         if (linked.size() > 0 && randDir) {
linked.removeFirst();
else {
linked.addLast(values[i]);
endTime = System.currentTimeMillis();
linked.clear();
System.out.println("linked:"+(endTime-startTime));
startTime = System.currentTimeMillis();
for (int i = 0; i < values.length; i++) {
if (array.size() > 0 && randDir[i]) {
array.remove(0);
else {
array.add(values[i]);
endTime = System.currentTimeMillis();
System.out.println("array:"+(endTime-startTime));
array.clear();