public class Vector<E>

  1. Object
  2. AbstractCollection<E>
  3. AbstractList<E>
  4. Vector

ImplementsCollection<E>, Iterable<E>, List<E>, RandomAccess

Known subtypesStack

Vector is a variable size contiguous indexable array of objects. The size of the vector is the number of objects it contains. The capacity of the vector is the number of objects it can hold.

Objects may be inserted at any position up to the size of the vector, thus increasing the size of the vector. Objects at any position in the vector may be removed, thus shrinking the size of the Vector. Objects at any position in the Vector may be replaced, which does not affect the vector’s size.

The capacity of a vector may be specified when the vector is created. If the capacity of the vector is exceeded, the capacity is increased (doubled by default).

See also

Fields

protected int elementCountThe number of elements or the size of the vector.
protected Object[] elementDataThe elements of the vector.
protected int capacityIncrementHow many elements should be added to the vector when it is detected that it needs to grow to accommodate extra entries.

Constructors

public Vector()Constructs a new vector using the default capacity.
public Vector(int capacity)Constructs a new vector using the specified capacity.
public Vector(int capacity, int capacityIncrement)Constructs a new vector using the specified capacity and capacity increment.
public Vector(Collection<? extends E> collection)Constructs a new instance of Vector containing the elements in collection.

Methods

public void add(int location, E object)Adds the specified object into this vector at the specified location.
public synchronized boolean add(E object)Adds the specified object at the end of this vector.
public synchronized boolean addAll(int location, Collection<? extends E> collection)Inserts the objects in the specified collection at the specified location in this vector.
public synchronized boolean addAll(Collection<? extends E> collection)Adds the objects in the specified collection to the end of this vector.
public synchronized void addElement(E object)Adds the specified object at the end of this vector.
public synchronized int capacity()Returns the number of elements this vector can hold without growing.
public void clear()Removes all elements from this vector, leaving it empty.
public boolean contains(Object object)Searches this vector for the specified object.
public synchronized boolean containsAll(Collection<?> collection)Searches this vector for all objects in the specified collection.
public synchronized void copyInto(Object[] elements)Attempts to copy elements contained by this Vector into the corresponding elements of the supplied Object array.
public synchronized E elementAt(int location)Returns the element at the specified location in this vector.
public Enumeration<E> elements()Returns an enumeration on the elements of this vector.
public synchronized void ensureCapacity(int minimumCapacity)Ensures that this vector can hold the specified number of elements without growing.
public synchronized boolean equals(Object object)Compares the specified object to this vector and returns if they are equal.
public synchronized E firstElement()Returns the first element in this vector.
public E get(int location)Returns the element at the specified location in this vector.
public synchronized int hashCode()Returns an integer hash code for the receiver.
public int indexOf(Object object)Searches in this vector for the index of the specified object.
public synchronized int indexOf(Object object, int location)Searches in this vector for the index of the specified object.
public synchronized void insertElementAt(E object, int location)Inserts the specified object into this vector at the specified location.
public synchronized boolean isEmpty()Returns if this vector has no elements, a size of zero.
public synchronized E lastElement()Returns the last element in this vector.
public synchronized int lastIndexOf(Object object)Searches in this vector for the index of the specified object.
public synchronized int lastIndexOf(Object object, int location)Searches in this vector for the index of the specified object.
public synchronized E remove(int location)Removes the object at the specified location from this vector.
public boolean remove(Object object)Removes the first occurrence, starting at the beginning and moving towards the end, of the specified object from this vector.
public synchronized boolean removeAll(Collection<?> collection)Removes all occurrences in this vector of each object in the specified Collection.
public synchronized void removeAllElements()Removes all elements from this vector, leaving the size zero and the capacity unchanged.
public synchronized boolean removeElement(Object object)Removes the first occurrence, starting at the beginning and moving towards the end, of the specified object from this vector.
public synchronized void removeElementAt(int location)Removes the element found at index position location from this Vector.
protected void removeRange(int start, int end)Removes the objects in the specified range from the start to the, but not including, end index.
public synchronized boolean retainAll(Collection<?> collection)Removes all objects from this vector that are not contained in the specified collection.
public synchronized E set(int location, E object)Replaces the element at the specified location in this vector with the specified object.
public synchronized void setElementAt(E object, int location)Replaces the element at the specified location in this vector with the specified object.
public synchronized void setSize(int length)Sets the size of this vector to the specified size.
public synchronized int size()Returns the number of elements in this vector.
public synchronized List<E> subList(int start, int end)Returns a List of the specified portion of this vector from the start index to one less than the end index.
public synchronized Object[] toArray()Returns a new array containing all elements contained in this vector.
public synchronized <T> T[] toArray(T[] contents)Returns an array containing all elements contained in this vector.
public synchronized String toString()Returns the string representation of this vector.
public synchronized void trimToSize()Sets the capacity of this vector to be the same as the size.

Inherited fields

From AbstractList

modCount

Inherited methods

From AbstractList

iterator, listIterator, listIterator

From Object

getClass, notify, notifyAll, wait, wait, wait, clone

From Collection

removeIf

From Iterable

forEach

From List

replaceAll, sort

Field details

elementCount

protected int elementCount
The number of elements or the size of the vector.

elementData

protected Object[] elementData
The elements of the vector.

capacityIncrement

protected int capacityIncrement
How many elements should be added to the vector when it is detected that it needs to grow to accommodate extra entries. If this value is zero or negative the size will be doubled if an increase is needed.

Constructor details

Vector

public Vector()
Constructs a new vector using the default capacity.

Vector

public Vector(int capacity)
Constructs a new vector using the specified capacity.

Parameters

capacity int
the initial capacity of the new vector.

Throws

IllegalArgumentException
if capacity is negative.

Vector

public Vector(int capacity, int capacityIncrement)
Constructs a new vector using the specified capacity and capacity increment.

Parameters

capacity int
the initial capacity of the new vector.
capacityIncrement int
the amount to increase the capacity when this vector is full.

Throws

IllegalArgumentException
if capacity is negative.

Vector

public Vector(Collection<? extends E> collection)
Constructs a new instance of Vector containing the elements in collection. The order of the elements in the new Vector is dependent on the iteration order of the seed collection.

Parameters

collection Collection<? extends E>
the collection of elements to add.

Method details

add

public void add(int location, E object)
Adds the specified object into this vector at the specified location. The object is inserted before any element with the same or a higher index increasing their index by 1. If the location is equal to the size of this vector, the object is added at the end.

Parameters

location int
the index at which to insert the element.
object E
the object to insert in this vector.

Throws

ArrayIndexOutOfBoundsException
if location size().
UnsupportedOperationException
if adding to this List is not supported.
ClassCastException
if the class of the object is inappropriate for this List
IllegalArgumentException
if the object cannot be added to this List
IndexOutOfBoundsException
if location = size()

See also

add

public synchronized boolean add(E object)
Adds the specified object at the end of this vector.

Parameters

object E
the object to add to the vector.

Returns

true

addAll

public synchronized boolean addAll(int location, Collection<? extends E> collection)
Inserts the objects in the specified collection at the specified location in this vector. The objects are inserted in the order in which they are returned from the Collection iterator. The elements with an index equal or higher than location have their index increased by the size of the added collection.

Parameters

location int
the location to insert the objects.
collection Collection<? extends E>
the collection of objects.

Returns

true if this vector is modified, false otherwise.

Throws

ArrayIndexOutOfBoundsException
if location size().

addAll

public synchronized boolean addAll(Collection<? extends E> collection)
Adds the objects in the specified collection to the end of this vector.

Parameters

collection Collection<? extends E>
the collection of objects.

Returns

true if this vector is modified, false otherwise.

addElement

public synchronized void addElement(E object)
Adds the specified object at the end of this vector.

Parameters

object E
the object to add to the vector.

capacity

public synchronized int capacity()
Returns the number of elements this vector can hold without growing.

Returns

the capacity of this vector.

See also

clear

public void clear()
Removes all elements from this vector, leaving it empty.

Throws

UnsupportedOperationException
if removing from this list is not supported.

See also

contains

public boolean contains(Object object)
Searches this vector for the specified object.

Parameters

object Object
the object to look for in this vector.

Returns

true if object is an element of this vector, false otherwise.

See also

containsAll

public synchronized boolean containsAll(Collection<?> collection)
Searches this vector for all objects in the specified collection.

Parameters

collection Collection<?>
the collection of objects.

Returns

true if all objects in the specified collection are elements of this vector, false otherwise.

copyInto

public synchronized void copyInto(Object[] elements)
Attempts to copy elements contained by this Vector into the corresponding elements of the supplied Object array.

Parameters

elements Object[]
the Object array into which the elements of this vector are copied.

Throws

IndexOutOfBoundsException
if elements is not big enough.

See also

elementAt

public synchronized E elementAt(int location)
Returns the element at the specified location in this vector.

Parameters

location int
the index of the element to return in this vector.

Returns

the element at the specified location.

Throws

ArrayIndexOutOfBoundsException
if location = size().

See also

elements

public Enumeration<E> elements()
Returns an enumeration on the elements of this vector. The results of the enumeration may be affected if the contents of this vector is modified.

Returns

an enumeration of the elements of this vector.

See also

ensureCapacity

public synchronized void ensureCapacity(int minimumCapacity)
Ensures that this vector can hold the specified number of elements without growing.

Parameters

minimumCapacity int
the minimum number of elements that this vector will hold before growing.

See also

equals

public synchronized boolean equals(Object object)
Compares the specified object to this vector and returns if they are equal. The object must be a List which contains the same objects in the same order.

Parameters

object Object
the object to compare with this object

Returns

true if the specified object is equal to this vector, false otherwise.

See also

firstElement

public synchronized E firstElement()
Returns the first element in this vector.

Returns

the element at the first position.

Throws

NoSuchElementException
if this vector is empty.

See also

get

public E get(int location)
Returns the element at the specified location in this vector.

Parameters

location int
the index of the element to return in this vector.

Returns

the element at the specified location.

Throws

ArrayIndexOutOfBoundsException
if location = size().

See also

hashCode

public synchronized int hashCode()
Returns an integer hash code for the receiver. Objects which are equal return the same value for this method.

Returns

the receiver’s hash.

See also

indexOf

public int indexOf(Object object)
Searches in this vector for the index of the specified object. The search for the object starts at the beginning and moves towards the end of this vector.

Parameters

object Object
the object to find in this vector.

Returns

the index in this vector of the specified element, -1 if the element isn’t found.

See also

indexOf

public synchronized int indexOf(Object object, int location)
Searches in this vector for the index of the specified object. The search for the object starts at the specified location and moves towards the end of this vector.

Parameters

object Object
the object to find in this vector.
location int
the index at which to start searching.

Returns

the index in this vector of the specified element, -1 if the element isn’t found.

Throws

ArrayIndexOutOfBoundsException
if location < 0.

See also

insertElementAt

public synchronized void insertElementAt(E object, int location)
Inserts the specified object into this vector at the specified location. This object is inserted before any previous element at the specified location. All elements with an index equal or greater than location have their index increased by 1. If the location is equal to the size of this vector, the object is added at the end.

Parameters

object E
the object to insert in this vector.
location int
the index at which to insert the element.

Throws

ArrayIndexOutOfBoundsException
if location size().

See also

isEmpty

public synchronized boolean isEmpty()
Returns if this vector has no elements, a size of zero.

Returns

true if this vector has no elements, false otherwise.

See also

lastElement

public synchronized E lastElement()
Returns the last element in this vector.

Returns

the element at the last position.

Throws

NoSuchElementException
if this vector is empty.

See also

lastIndexOf

public synchronized int lastIndexOf(Object object)
Searches in this vector for the index of the specified object. The search for the object starts at the end and moves towards the start of this vector.

Parameters

object Object
the object to find in this vector.

Returns

the index in this vector of the specified element, -1 if the element isn’t found.

See also

lastIndexOf

public synchronized int lastIndexOf(Object object, int location)
Searches in this vector for the index of the specified object. The search for the object starts at the specified location and moves towards the start of this vector.

Parameters

object Object
the object to find in this vector.
location int
the index at which to start searching.

Returns

the index in this vector of the specified element, -1 if the element isn’t found.

Throws

ArrayIndexOutOfBoundsException
if location >= size().

See also

remove

public synchronized E remove(int location)
Removes the object at the specified location from this vector. All elements with an index bigger than location have their index decreased by 1.

Parameters

location int
the index of the object to remove.

Returns

the removed object.

Throws

IndexOutOfBoundsException
if location = size().

remove

public boolean remove(Object object)
Removes the first occurrence, starting at the beginning and moving towards the end, of the specified object from this vector. All elements with an index bigger than the element that gets removed have their index decreased by 1.

Parameters

object Object
the object to remove from this vector.

Returns

true if the specified object was found, false otherwise.

See also

removeAll

public synchronized boolean removeAll(Collection<?> collection)
Removes all occurrences in this vector of each object in the specified Collection.

Parameters

collection Collection<?>
the collection of objects to remove.

Returns

true if this vector is modified, false otherwise.

See also

removeAllElements

public synchronized void removeAllElements()
Removes all elements from this vector, leaving the size zero and the capacity unchanged.

See also

removeElement

public synchronized boolean removeElement(Object object)
Removes the first occurrence, starting at the beginning and moving towards the end, of the specified object from this vector. All elements with an index bigger than the element that gets removed have their index decreased by 1.

Parameters

object Object
the object to remove from this vector.

Returns

true if the specified object was found, false otherwise.

See also

removeElementAt

public synchronized void removeElementAt(int location)
Removes the element found at index position location from this Vector. All elements with an index bigger than location have their index decreased by 1.

Parameters

location int
the index of the element to remove.

Throws

ArrayIndexOutOfBoundsException
if location = size().

See also

removeRange

protected void removeRange(int start, int end)
Removes the objects in the specified range from the start to the, but not including, end index. All elements with an index bigger than or equal to end have their index decreased by end - start.

Parameters

start int
the index at which to start removing.
end int
the index one past the end of the range to remove.

Throws

IndexOutOfBoundsException
if start end or end > size().
UnsupportedOperationException
if removing from this list is not supported.

retainAll

public synchronized boolean retainAll(Collection<?> collection)
Removes all objects from this vector that are not contained in the specified collection.

Parameters

collection Collection<?>
the collection of objects to retain.

Returns

true if this vector is modified, false otherwise.

See also

set

public synchronized E set(int location, E object)
Replaces the element at the specified location in this vector with the specified object.

Parameters

location int
the index at which to put the specified object.
object E
the object to add to this vector.

Returns

the previous element at the location.

Throws

ArrayIndexOutOfBoundsException
if location = size().

See also

setElementAt

public synchronized void setElementAt(E object, int location)
Replaces the element at the specified location in this vector with the specified object.

Parameters

object E
the object to add to this vector.
location int
the index at which to put the specified object.

Throws

ArrayIndexOutOfBoundsException
if location = size().

See also

setSize

public synchronized void setSize(int length)
Sets the size of this vector to the specified size. If there are more than length elements in this vector, the elements at end are lost. If there are less than length elements in the vector, the additional elements contain null.

Parameters

length int
the new size of this vector.

See also

size

public synchronized int size()
Returns the number of elements in this vector.

Returns

the number of elements in this vector.

See also

subList

public synchronized List<E> subList(int start, int end)
Returns a List of the specified portion of this vector from the start index to one less than the end index. The returned List is backed by this vector so changes to one are reflected by the other.

Parameters

start int
the index at which to start the sublist.
end int
the index one past the end of the sublist.

Returns

a List of a portion of this vector.

Throws

IndexOutOfBoundsException
if start size().
IllegalArgumentException
if start > end.

toArray

public synchronized Object[] toArray()
Returns a new array containing all elements contained in this vector.

Returns

an array of the elements from this vector.

toArray

public synchronized <T> T[] toArray(T[] contents)
Returns an array containing all elements contained in this vector. If the specified array is large enough to hold the elements, the specified array is used, otherwise an array of the same type is created. If the specified array is used and is larger than this vector, the array element following the collection elements is set to null.

Parameters

contents T[]
the array to fill.

Returns

an array of the elements from this vector.

Throws

ArrayStoreException
if the type of an element in this vector cannot be stored in the type of the specified array.

toString

public synchronized String toString()
Returns the string representation of this vector.

Returns

the string representation of this vector.

See also

trimToSize

public synchronized void trimToSize()
Sets the capacity of this vector to be the same as the size.

See also