Interface QueueADT<E>

All Known Implementing Classes:

PriorityQueue, Queue

public interface QueueADT<E>

An ordered collection of items, where items are added to the rear and removed from the front.

Author:

CS367

Method Summary

Modifier and Type	Method and Description
void	clear() Removes all items in the queue leaving an empty queue.
E	dequeue() Removes an item from the front of the Queue and returns it.
void	enqueue(E item) Adds an item to the rear of the queue.
boolean	isEmpty() Returns true iff the Queue is empty.
E	peek() Returns the item at front of the Queue without removing it.
int	size() Returns the number of items in the Queue.

Method Detail

enqueue

void enqueue(E item)

Adds an item to the rear of the queue.

Parameters:

item - the item to add to the queue.

Throws:

java.lang.IllegalArgumentException - if item is null.

dequeue

E dequeue()

Removes an item from the front of the Queue and returns it.

Returns:

the front item in the queue.

Throws:

EmptyQueueException - if the queue is empty.

peek

E peek()

Returns the item at front of the Queue without removing it.

Returns:

the front item in the queue.

Throws:

EmptyQueueException - if the queue is empty.

isEmpty

boolean isEmpty()

Returns true iff the Queue is empty.

Returns:

true if queue is empty; otherwise false.

clear

void clear()

Removes all items in the queue leaving an empty queue.

size

int size()

Returns the number of items in the Queue.

Returns:

the size of the queue.