How to initialize a Queue in the same statement

Question

In arrays, elements can be added at the beginning in the following manner

int[] array = {1,2,3,4,5};

similarly how to add multiple entries to a Queue? like,

Queue<Integer> queue = {1,2,3,4,5};

is there any way to do this?

Answer 1

First you must choose which Queue implementation you wish to instantiate. Let's assume you are choosing LinkedList (which implements Queue ).

Like any Collection, LinkedList has a constructor that takes a Collection and adds the elements of that Collection to the list.

For example:

Queue<Integer> queue = new LinkedList<>(Arrays.asList(new Integer[]{1,2,3,4,5}));

or (as PaulrBear correctly commented):

Queue<Integer> queue = new LinkedList<>(Arrays.asList(1,2,3,4,5));

Or you can take advantage of Java 8 Streams :

Queue<Integer> queue = IntStream.of(1,2,3,4,5)
                                .boxed()
                                .collect(Collectors.toCollection(LinkedList::new));