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Interface jdsl.simple.api.Queue

public interface Queue
Interface for a queue.

A queue is a collection of elements that are inserted and removed according to the first-in first-out principle.

Version:
$Revision: 1.2 $, $Date: 1998/07/02 21:24:43 $
Author:
Michael T. Goodrich, Natasha Gelfand, Mark Handy, Roberto Tamassia
See Also:
QueueEmptyException, Stack, Deque

Method Index

o dequeue()
Remove the element at the front.
o enqueue(Object)
Insert an element at the rear.
o front()
Inspect the element at the front, without removing it or otherwise changing the queue.
o isEmpty()
Return true if and only if the queue is empty.
o size()
Return the number of elements.

Methods

o size 
 public abstract int size()
Return the number of elements.

Returns:
number of elements in the queue.
o isEmpty 
 public abstract boolean isEmpty()
Return true if and only if the queue is empty.

Returns:
true if the queue is empty, false otherwise.
o front 
 public abstract Object front() throws QueueEmptyException
Inspect the element at the front, without removing it or otherwise changing the queue.

Returns:
element at the front of the queue
Throws: QueueEmptyException
if the queue is empty
o enqueue 
 public abstract void enqueue(Object element)
Insert an element at the rear.

Parameters:
element - new element to be inserted.
o dequeue 
 public abstract Object dequeue() throws QueueEmptyException
Remove the element at the front.

Returns:
element removed. 
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