.java

package Question1;

import java.util.LinkedList;

public class Question1 implements Runnable {
    // Linkedlist is faster if your search for data in the beginning or the
    // middle of the array
    private static final LinkedList<Character> infiList = new LinkedList<>();


    //arraylist append to the end of the array, which is normally faster in
    // this situation

    // static ArrayList<Character> infiList = new ArrayList<Character>();

    public static void main(String[] args) {
        // creates a new Question object
        Question1 threadTester = new Question1();

        // creates new Threads and pass in the threadTester object
        Thread thread1 = new Thread(threadTester);
        Thread thread2 = new Thread(threadTester);
        Thread thread3 = new Thread(threadTester);

        // starts 3 threads
        thread1.start();
        thread2.start();
        thread3.start();

    }

    // Synchronized is lock  this resource until a thread has finished it, the next thread gain access to the resource
    public synchronized void run() {
        //creates and initialises variable


        // whilst true, then it will keep running infinitely
        while (true) {

            //creates a Character object which is a wrapper class for primitive type char, this is initialises at letter A
            char characters = 'A';

            // while is less or equal to Z
            while (characters <= 'Z') {
                // System.out.println(characters +",");

                // add characters to the infiList LinkedList
                infiList.add(characters);
                // Print out the List , ie get the last element in the array and print it
                System.out.println(infiList.get(infiList.size() - 1));
                // increments the character counter
                characters++;

            }

        }

    }

}