Queue

public class QueueTest {
    public static void main(String[] args){
        Queue<Integer> queue = new LinkedList<>() ;
        queue.offer(5);
        queue.offer(3);
        System.out.println(queue.size()); //2
        System.out.println(queue.poll()); //5
        System.out.println(queue.peek()); //3
        System.out.println(queue.isEmpty()); //false
        System.out.println(queue.poll()); //3
        System.out.println(queue.isEmpty()); //true
    }
}