Remove all items from the queue
[items]
(array): an array of items to add to the queue
Remove and return the first item in the queue
(*): removes and returns the last item in the queue
Add an item to the end of the queue
item
(*): an item to add to the queue
Add multiple items to the end of the queue
items
(*[]): an array of items to be added to the queue
Return the first item in the queue
(*): the last item in the queue
(number): The number of items in the queue