java.util
Class Vector

java.lang.Object
  |
  +--java.util.Vector

Direct Known Subclasses:

Stack

public class Vector

extends Object

Implement a growable array of objects

Field Summary

protected int	capacityIncrement The amount to increment the size by
protected int	elementCount number of elements
protected Object[]	elementData The element data

Constructor Summary

Vector()
Create a new vector

Vector(int ic)
Create a new vector of the particular size

Vector(int ic, int ci)
Create a new vector of a particular size

Method Summary

void	addElement(Object obj) Add an element at the end of the Vector.
int	capacity() Return the current capacity - not the size
boolean	contains(Object elem) Does it contain an object
void	copyInto(Object[] dest) Copy the components into the array
Object	elementAt(int index) Return the element at the particular position
Enumeration	elements() Return the elements
void	ensureCapacity(int minCapacity) Ensure there is capacity
Object	firstElement() Return the first element in the vector
int	indexOf(Object elem) Return the index of the element
int	indexOf(Object elem, int index) Return the index of the element
void	insertElementAt(Object obj, int index) Insert an element at a particular location
boolean	isEmpty() Test to see if it is empty
Object	lastElement() Return the last element in the vector
int	lastIndexOf(Object elem) Return the last index of the element
int	lastIndexOf(Object elem, int index) Return the last index of the element
void	removeAllElements() Remove all the elements
boolean	removeElement(Object obj) Remove the first element with the particular value
void	removeElementAt(int index) Remove the element at a particular position and reduce the size of the vector
void	setElementAt(Object obj, int index) Set the element at a particular position
void	setSize(int newSize) Set the size
int	size() Return the current size
java.lang.String	toString() Convert to a string
void	trimToSize() Trim the capacity to the current size

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

capacityIncrement

protected int capacityIncrement

The amount to increment the size by

elementCount

protected int elementCount

number of elements

elementData

protected Object[] elementData

The element data

Constructor Detail

Vector

public Vector(int ic,
              int ci)
       throws IllegalArgumentException

Create a new vector of a particular size

Parameters:

ic - The initial capacity

ci - The capacity increment

Throws:

IllegalArgumentException - if the initial capacity is negative

Vector

public Vector(int ic)
       throws IllegalArgumentException

Create a new vector of the particular size

Parameters:

ic - The initial capacity

Throws:

IllegalArgumentException - if the initial capacity is negative

Vector

public Vector()

Create a new vector

Method Detail

addElement

public void addElement(Object obj)

Add an element at the end of the Vector. If there was not room in the Vector then the capacity is increased as follows

1. If the capacityIncrement is greater than zero then the capacity is increased by this amount
2. If the capacityIncrement is less than or equal to zero then the capacity is increased by the size of the vector, unless the size is also zsero in which case the capacity is increased by 1

Parameters:

obj - The object to add

capacity

public int capacity()

Return the current capacity - not the size

Returns:

the capacity

contains

public boolean contains(Object elem)

Does it contain an object

Parameters:

elem - The element to find

Returns:

true if the element is here

copyInto

public void copyInto(Object[] dest)

Copy the components into the array

Parameters:

dest - The array to copy into

Throws:

ArrayIndexOutOfBoundsException

ArrayStoreException - if the arrays are of incompatible types

NullPointerException - if the destination array is null

elementAt

public Object elementAt(int index)

Return the element at the particular position

Parameters:

index - The index

elements

public Enumeration elements()

Return the elements

Returns:

an enumeration over the elements

ensureCapacity

public void ensureCapacity(int minCapacity)

Ensure there is capacity

Parameters:

minCapacity - the minimum capacity required

firstElement

public Object firstElement()

Return the first element in the vector

Returns:

the element

indexOf

public int indexOf(Object elem)

Return the index of the element

Parameters:

elem - The element to find

Returns:

the index of the element or -1

indexOf

public int indexOf(Object elem,
                   int index)

Return the index of the element

Parameters:

elem - The element

index - The index to start from

Returns:

the index of the element or -1

insertElementAt

public void insertElementAt(Object obj,
                            int index)

Insert an element at a particular location

Parameters:

obj - The object to insert

index - The index to insert to

isEmpty

public boolean isEmpty()

Test to see if it is empty

Returns:

true if it is empty

lastIndexOf

public int lastIndexOf(Object elem)

Return the last index of the element

Parameters:

elem - The element

Returns:

the index of the element or -1

lastIndexOf

public int lastIndexOf(Object elem,
                       int index)

Return the last index of the element

Parameters:

elem - The element

index - The index to start from

Returns:

the index of the element or -1

lastElement

public Object lastElement()

Return the last element in the vector

Returns:

the element

removeAllElements

public void removeAllElements()

Remove all the elements

removeElement

public boolean removeElement(Object obj)

Remove the first element with the particular value

Parameters:

obj -

Returns:

true if something was removed

removeElementAt

public void removeElementAt(int index)

Remove the element at a particular position and reduce the size of the vector

Parameters:

index - The index to remove

setElementAt

public void setElementAt(Object obj,
                         int index)

Set the element at a particular position

Parameters:

obj - The element to set

index - The index to set it at

setSize

public void setSize(int newSize)

Set the size

Parameters:

newSize - The new size

size

public int size()

Return the current size

Returns:

the size

trimToSize

public void trimToSize()

Trim the capacity to the current size

toString

public java.lang.String toString()

Convert to a string

Overrides:

toString in class Object

Returns:

the string representation