Java Reference
In-Depth Information
Element >= 4 is 4
Element < 12 is 82
Element <= 12 is 82
Element > 12 is 11
Element >= 12 is 11
Thefirstfouroutputlinesbeginningwith
Element
pertaintoanascending-orderset
where the element being matched (
4
) is a member of the set. The second four
Ele-
ment
-prefixedlinespertaintoadescending-ordersetwheretheelementbeingmatched
(
12
) is not a member.
Aswellaslettingyouconvenientlylocatesetelementsviaitsclosest-matchmethods
(
ceiling()
,
floor()
,
higher()
,and
lower()
),
NavigableSet
letsyoure-
turnsetviewscontainingallelementswithincertainranges,asdemonstratedbythefol-
lowing examples:
•
ns.subSet(-13, true, 9, true)
: Return all elements from
-13
through
9
.
•
ns.tailSet(-6, false)
: Return all elements greater than
-6
.
•
ns.headSet(4, true)
: Return all elements less than or equal to
4
.
Finally,youcanreturnandremovefromthesetthefirst(lowest)elementbycalling
pollFirst()
andthelast(highest)elementbycalling
pollLast()
.Forexample,
ns.pollFirst()
removes and returns
-13
, and
ns.pollLast()
removes and
returns
-82
.
Queue
A
queue
is a collection in which elements are stored and retrieved in a specific order.
Most queues are categorized as one of the following:
•
First-in, first-out (FIFO) queue
:Elementsareinsertedatthequeue's
tail
andre-
moved at the queue's
head
.
•
Last-in, first-out (LIFO) queue
:Elementsareinsertedandremovedatoneend
of the queue such that the last element inserted is the first element retrieved.
This kind of queue behaves as a
stack
.
•
Priority queue
:Elementsareinsertedaccordingtotheirnaturalordering,orac-
cording to a comparator that is supplied to the queue implementation.
Queue
, whose generic type is
Queue<E>
, extends
Collection
, redeclaring
add()
toadjustitscontract(insertthespecifiedelementintothisqueueifitispossible
