DAT
Interface Queue

public interface Queue

Queue interface.

Method Summary

java.lang.Object	dequeue() remove the item at the front of the queue
void	enqueue(java.lang.Object a) insert an item at the back of the queue
java.lang.Object	examine() examine the item at the front of the queue
boolean	isEmpty() test whether the queue is empty

Method Detail

isEmpty

public boolean isEmpty()

test whether the queue is empty

Returns:

true if the queue is empty, false otherwise

enqueue

public void enqueue(java.lang.Object a)

insert an item at the back of the queue

Parameters:

a - the item to insert

examine

public java.lang.Object examine()
                         throws Underflow

examine the item at the front of the queue

Returns:

the first item

Throws:

Underflow - if the queue is empty

dequeue

public java.lang.Object dequeue()
                         throws Underflow

remove the item at the front of the queue

Returns:

the removed item

Throws:

Underflow - if the queue is empty