// collections/QueueDemo.java // (c)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. // Upcasting to a Queue from a LinkedList import java.util.*; public class QueueDemo { public static void printQ(Queue queue) { while(queue.peek() != null) System.out.print(queue.remove() + " "); System.out.println(); } public static void main(String[] args) { Queue queue = new LinkedList<>(); Random rand = new Random(47); for(int i = 0; i < 10; i++) queue.offer(rand.nextInt(i + 10)); printQ(queue); Queue qc = new LinkedList<>(); for(char c : "Brontosaurus".toCharArray()) qc.offer(c); printQ(qc); } } /* Output: 8 1 1 1 5 14 3 1 0 1 B r o n t o s a u r u s */