ArrayQueue

java.lang.Object
- net.datastructures.ArrayQueue<E>

All Implemented Interfaces:

Queue<E>
```
public class ArrayQueue<E>
extends Object
implements Queue<E>
```
Implementation of the queue ADT using a fixed-length array. All operations are performed in constant time. An exception is thrown if an enqueue operation is attempted when the size of the queue is equal to the length of the array.

Field Summary

Fields
Modifier and Type Field and Description

static int CAPACITY
Default array capacity.

Fields
Modifier and Type	Field and Description
`static int`	`CAPACITY` Default array capacity.

Constructor Summary

Constructors
Constructor and Description
`ArrayQueue()` Constructs an empty queue using the default array capacity.
`ArrayQueue(int capacity)` Constructs and empty queue with the given array capacity.

Method Summary

Methods
Modifier and Type	Method and Description
`E`	`dequeue()` Removes and returns the first element of the queue.
`void`	`enqueue(E e)` Inserts an element at the rear of the queue.
`E`	`first()` Returns, but does not remove, the first element of the queue.
`boolean`	`isEmpty()` Tests whether the queue is empty.
`int`	`size()` Returns the number of elements in the queue.
`String`	`toString()` Returns a string representation of the queue as a list of elements.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - CAPACITY
```
public static final int CAPACITY
```
    Default array capacity.
    
    See Also:
    Constant Field Values
- Constructor Detail
  - ArrayQueue
```
public ArrayQueue()
```
    Constructs an empty queue using the default array capacity.
  - ArrayQueue
```
public ArrayQueue(int capacity)
```
    Constructs and empty queue with the given array capacity.
    
    Parameters:
    capacity - length of the underlying array
- Method Detail
  - size
```
public int size()
```
    Returns the number of elements in the queue.
    
    Specified by:
    
    size in interface Queue<E>
    
    Returns:
    number of elements in the queue
  - isEmpty
```
public boolean isEmpty()
```
    Tests whether the queue is empty.
    
    Specified by:
    
    isEmpty in interface Queue<E>
    
    Returns:
    true if the queue is empty, false otherwise
  - enqueue
```
public void enqueue(E e)
             throws IllegalStateException
```
    Inserts an element at the rear of the queue. This method runs in O(1) time.
    
    Specified by:
    
    enqueue in interface Queue<E>
    
    Parameters:
    e - new element to be inserted
    
    Throws:
    
    IllegalStateException - if the array storing the elements is full
  - first
```
public E first()
```
    Returns, but does not remove, the first element of the queue.
    
    Specified by:
    
    first in interface Queue<E>
    
    Returns:
    the first element of the queue (or null if empty)
  - dequeue
```
public E dequeue()
```
    Removes and returns the first element of the queue.
    
    Specified by:
    
    dequeue in interface Queue<E>
    
    Returns:
    element removed (or null if empty)
  - toString
```
public String toString()
```
    Returns a string representation of the queue as a list of elements. This method runs in O(n) time, where n is the size of the queue.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    textual representation of the queue.

Class ArrayQueue<E>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

CAPACITY

Constructor Detail

ArrayQueue

ArrayQueue

Method Detail

size

isEmpty

enqueue

first

dequeue

toString