如何打印通用链表队列中的所有元素？

Question

This is the current method I'm working with. newt is the name of the Generic LinkedList Queue .

newt.peek() returns the data inside of the head of the queue .

I'm not sure how to go through each element in the queue (this is my first time working with a queue) and print the data in each one.

//Print all elements of the queue.
public void printProcessQueue() {
    boolean hasMore = true;
    while (hasMore) {
        if (newt.peek() != null) {
            System.out.println(newt.head);
            //Cannot figure out how to get the next in queue
        }
    }
}

Answer 1

how to go through each element in the queue and print the data in each one

You can do it by removing the head of the queue in a loop until the queue is not empty:

public void printQueue() {
    while (!queue.isEmpty()) {              // basically you can use `queue.peek() != null`, but `isEmpty()` is more preferable because it's more expressive
        System.out.println(queue.remove()); // or queue.poll()
    }
}

If you're not OK with removing all the elements from the queue , then you can make use of the iterator . But note that iterator created over the elements of the queue will not necessarily guarantee to traverse them in any specific order. It will depend on the implementation: for instance, ArrayDeque and LinkedList give you such guarantee, but PriorityQueue doesn't.

public void printQueue() {
    Iterator<MyType> iterator = queue.iterator();
    while (iterator.hasNext()) {
        System.out.println(iterator.next());
    }
}

Sidenote: when you need a Queue (or Deque ) favor ArrayDeque over LinkedList as a more performant implementation.