Class Vector<E>

java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractList<E>
java.util.Vector<E>
All Implemented Interfaces:
Iterable<E>, Collection<E>, List<E>, RandomAccess
Direct Known Subclasses:
Stack
public class Vector<E> extends AbstractList<E> implements List<E>, RandomAccess

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
  • java.lang.StringBuffer

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    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.
    protected int
    elementCount
    The number of elements or the size of the vector.
    protected Object[]
    elementData
    The elements of the vector.

    Fields inherited from class AbstractList

    modCount

  • Constructor Summary

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

  • Method Summary

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

    Methods inherited from class AbstractList

    iterator, listIterator, listIterator

    Methods inherited from class Object

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

    Methods inherited from interface List

    iterator, listIterator, listIterator

  • 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: 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: the initial capacity of the new vector.

      • capacityIncrement: 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: 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: the index at which to insert the element.

      • object: the object to insert in this vector.

      Throws
      • ArrayIndexOutOfBoundsException: if location size().
      See also

      • #addElement

      • #size

      Specified by:
      add in interface List<E>
      Overrides:
      add in class AbstractList<E>

    • add

      public boolean add(E object)

      Adds the specified object at the end of this vector.

      Parameters
      • object: the object to add to the vector.
      Returns

      true

      Specified by:
      add in interface Collection<E>
      Specified by:
      add in interface List<E>
      Overrides:
      add in class AbstractList<E>
      Returns:

      true if this Collection is modified, false otherwise.

      Throws

      • UnsupportedOperationException: if adding to this Collection is not supported.

      • ClassCastException: @throws ClassCastException if the class of the object is inappropriate for this collection.

      • IllegalArgumentException: if the object cannot be added to this Collection.

      • NullPointerException: if null elements cannot be added to the Collection.

    • addAll

      public 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: the location to insert the objects.

      • collection: the collection of objects.

      Returns

      true if this vector is modified, false otherwise.

      Throws
      • ArrayIndexOutOfBoundsException: if location size().
      Specified by:
      addAll in interface List<E>
      Overrides:
      addAll in class AbstractList<E>
      Returns:

      true if this List has been modified through the insertion, false otherwise (i.e. if the passed collection was empty).

      Throws

      • UnsupportedOperationException: if adding to this List is not supported.

      • ClassCastException: @throws ClassCastException if the class of an object is inappropriate for this List.

      • IllegalArgumentException: if an object cannot be added to this List.

      • IndexOutOfBoundsException: if location size()

    • addAll

      public boolean addAll(Collection<? extends E> collection)

      Adds the objects in the specified collection to the end of this vector.

      Parameters
      • collection: the collection of objects.
      Returns

      true if this vector is modified, false otherwise.

      Specified by:
      addAll in interface Collection<E>
      Specified by:
      addAll in interface List<E>
      Overrides:
      addAll in class AbstractCollection<E>
      Returns:

      true if this Collection is modified, false otherwise.

      Throws

      • UnsupportedOperationException: if adding to this Collection is not supported.

      • ClassCastException: @throws ClassCastException if the class of an object is inappropriate for this Collection.

      • IllegalArgumentException: if an object cannot be added to this Collection.

      • NullPointerException: @throws NullPointerException if collection is null, or if it contains null elements and this Collection does not support such elements.

    • addElement

      public void addElement(E object)

      Adds the specified object at the end of this vector.

      Parameters
      • object: the object to add to the vector.

    • capacity

      public int capacity()

      Returns the number of elements this vector can hold without growing.

      Returns

      the capacity of this vector.

      See also

      • #ensureCapacity

      • #size

    • clear

      public void clear()

      Removes all elements from this vector, leaving it empty.

      See also

      • #isEmpty

      • #size

      Specified by:
      clear in interface Collection<E>
      Specified by:
      clear in interface List<E>
      Overrides:
      clear in class AbstractList<E>

    • contains

      public boolean contains(Object object)

      Searches this vector for the specified object.

      Parameters
      • object: the object to look for in this vector.
      Returns
      Specified by:
      contains in interface Collection<E>
      Specified by:
      contains in interface List<E>
      Overrides:
      contains in class AbstractCollection<E>
      Returns:

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

      See also

      • #indexOf(Object)

      • #indexOf(Object, int)

      • java.lang.Object#equals

    • containsAll

      public boolean containsAll(Collection<?> collection)

      Searches this vector for all objects in the specified collection.

      Parameters
      • collection: the collection of objects.
      Returns
      Specified by:
      containsAll in interface Collection<E>
      Specified by:
      containsAll in interface List<E>
      Overrides:
      containsAll in class AbstractCollection<E>
      Returns:
      true if all objects in the specified collection are elements of this vector, false otherwise.

    • copyInto

      public void copyInto(Object[] elements)

      Attempts to copy elements contained by this Vector into the corresponding elements of the supplied Object array.

      Parameters
      • elements: @param elements the Object array into which the elements of this vector are copied.
      Throws
      • IndexOutOfBoundsException: if elements is not big enough.
      See also
      • #clone

    • elementAt

      public E elementAt(int location)

      Returns the element at the specified location in this vector.

      Parameters
      • location: the index of the element to return in this vector.
      Returns

      the element at the specified location.

      Throws
      • ArrayIndexOutOfBoundsException: if location = size().
      See also
      • #size

    • 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

      • #elementAt

      • Enumeration

    • ensureCapacity

      public void ensureCapacity(int minimumCapacity)

      Ensures that this vector can hold the specified number of elements without growing.

      Parameters
      • minimumCapacity: @param minimumCapacity the minimum number of elements that this vector will hold before growing.
      See also
      • #capacity

    • equals

      public 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: the object to compare with this object
      Returns
      Specified by:
      equals in interface Collection<E>
      Specified by:
      equals in interface List<E>
      Overrides:
      equals in class AbstractList<E>
      Returns:

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

      See also
      • #hashCode

    • firstElement

      public 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

      • #elementAt

      • #lastElement

      • #size

    • get

      public E get(int location)

      Returns the element at the specified location in this vector.

      Parameters
      • location: the index of the element to return in this vector.
      Returns

      the element at the specified location.

      Throws
      • ArrayIndexOutOfBoundsException: if location = size().
      See also
      • #size
      Specified by:
      get in interface List<E>
      Specified by:
      get in class AbstractList<E>

    • hashCode

      public 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
      • #equals
      Specified by:
      hashCode in interface Collection<E>
      Specified by:
      hashCode in interface List<E>
      Overrides:
      hashCode in class AbstractList<E>

    • 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: the object to find in this vector.
      Returns
      Specified by:
      indexOf in interface List<E>
      Overrides:
      indexOf in class AbstractList<E>
      Returns:

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

      See also

      • #contains

      • #lastIndexOf(Object)

      • #lastIndexOf(Object, int)

    • indexOf

      public 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: the object to find in this vector.

      • location: the index at which to start searching.

      Returns
      Returns:

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

      Throws
      • ArrayIndexOutOfBoundsException: if location < 0.
      See also

      • #contains

      • #lastIndexOf(Object)

      • #lastIndexOf(Object, int)

    • insertElementAt

      public 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: the object to insert in this vector.

      • location: the index at which to insert the element.

      Throws
      • ArrayIndexOutOfBoundsException: if location size().
      See also

      • #addElement

      • #size

    • isEmpty

      public boolean isEmpty()

      Returns if this vector has no elements, a size of zero.

      Returns
      Specified by:
      isEmpty in interface Collection<E>
      Specified by:
      isEmpty in interface List<E>
      Overrides:
      isEmpty in class AbstractCollection<E>
      Returns:

      true if this vector has no elements, false otherwise.

      See also
      • #size

    • lastElement

      public 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

      • #elementAt

      • #firstElement

      • #size

    • lastIndexOf

      public 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: the object to find in this vector.
      Returns
      Specified by:
      lastIndexOf in interface List<E>
      Overrides:
      lastIndexOf in class AbstractList<E>
      Returns:

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

      See also

      • #contains

      • #indexOf(Object)

      • #indexOf(Object, int)

    • lastIndexOf

      public 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: the object to find in this vector.

      • location: the index at which to start searching.

      Returns
      Returns:

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

      Throws
      • ArrayIndexOutOfBoundsException: if location >= size().
      See also

      • #contains

      • #indexOf(Object)

      • #indexOf(Object, int)

    • remove

      public 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: the index of the object to remove.
      Returns

      the removed object.

      Throws
      • IndexOutOfBoundsException: if location = size().
      Specified by:
      remove in interface List<E>
      Overrides:
      remove in class AbstractList<E>

    • 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: the object to remove from this vector.
      Returns
      Specified by:
      remove in interface Collection<E>
      Specified by:
      remove in interface List<E>
      Overrides:
      remove in class AbstractCollection<E>
      Returns:

      true if the specified object was found, false otherwise.

      See also

      • #removeAllElements

      • #removeElementAt

      • #size

    • removeAll

      public boolean removeAll(Collection<?> collection)

      Removes all occurrences in this vector of each object in the specified Collection.

      Parameters
      • collection: the collection of objects to remove.
      Returns

      true if this vector is modified, false otherwise.

      See also

      • #remove(Object)

      • #contains(Object)

      Specified by:
      removeAll in interface Collection<E>
      Specified by:
      removeAll in interface List<E>
      Overrides:
      removeAll in class AbstractCollection<E>
      Returns:

      true if this Collection is modified, false otherwise.

      Throws

      • UnsupportedOperationException: if removing from this Collection is not supported.

      • ClassCastException: @throws ClassCastException if one or more elements of collection isn't of the correct type.

      • NullPointerException: @throws NullPointerException if collection contains at least one null element and this Collection doesn't support null elements.

      • NullPointerException: if collection is null.

    • removeAllElements

      public void removeAllElements()

      Removes all elements from this vector, leaving the size zero and the capacity unchanged.

      See also

      • #isEmpty

      • #size

    • removeElement

      public 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: the object to remove from this vector.
      Returns
      Returns:

      true if the specified object was found, false otherwise.

      See also

      • #removeAllElements

      • #removeElementAt

      • #size

    • removeElementAt

      public 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: the index of the element to remove.
      Throws
      • ArrayIndexOutOfBoundsException: if location = size().
      See also

      • #removeElement

      • #removeAllElements

      • #size

    • 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: the index at which to start removing.

      • end: the index one past the end of the range to remove.

      Throws
      • IndexOutOfBoundsException: @throws IndexOutOfBoundsException if start end or end > size().
      Overrides:
      removeRange in class AbstractList<E>

    • retainAll

      public boolean retainAll(Collection<?> collection)

      Removes all objects from this vector that are not contained in the specified collection.

      Parameters
      • collection: the collection of objects to retain.
      Returns

      true if this vector is modified, false otherwise.

      See also
      • #remove(Object)
      Specified by:
      retainAll in interface Collection<E>
      Specified by:
      retainAll in interface List<E>
      Overrides:
      retainAll in class AbstractCollection<E>
      Returns:

      true if this Collection is modified, false otherwise.

      Throws

      • UnsupportedOperationException: if removing from this Collection is not supported.

      • ClassCastException: @throws ClassCastException if one or more elements of collection isn't of the correct type.

      • NullPointerException: @throws NullPointerException if collection contains at least one null element and this Collection doesn't support null elements.

      • NullPointerException: if collection is null.

    • set

      public E set(int location, E object)

      Replaces the element at the specified location in this vector with the specified object.

      Parameters

      • location: the index at which to put the specified object.

      • object: the object to add to this vector.

      Returns

      the previous element at the location.

      Throws
      • ArrayIndexOutOfBoundsException: if location = size().
      See also
      • #size
      Specified by:
      set in interface List<E>
      Overrides:
      set in class AbstractList<E>

    • setElementAt

      public void setElementAt(E object, int location)

      Replaces the element at the specified location in this vector with the specified object.

      Parameters

      • object: the object to add to this vector.

      • location: the index at which to put the specified object.

      Throws
      • ArrayIndexOutOfBoundsException: if location = size().
      See also
      • #size

    • setSize

      public 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: the new size of this vector.
      See also
      • #size

    • size

      public int size()

      Returns the number of elements in this vector.

      Returns

      the number of elements in this vector.

      See also

      • #elementCount

      • #lastElement

      Specified by:
      size in interface Collection<E>
      Specified by:
      size in interface List<E>
      Specified by:
      size in class AbstractCollection<E>
      Returns:
      how many objects this Collection contains, or Integer.MAX_VALUE if there are more than Integer.MAX_VALUE elements in this Collection.

    • subList

      public 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: the index at which to start the sublist.

      • end: 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.

      Specified by:
      subList in interface List<E>
      Overrides:
      subList in class AbstractList<E>
      Returns:

      a subList view of this list starting from start (inclusive), and ending with end (exclusive)

      Throws

      • IndexOutOfBoundsException: if (start size())

      • IllegalArgumentException: if (start > end)

    • toArray

      public Object[] toArray()

      Returns a new array containing all elements contained in this vector.

      Returns

      an array of the elements from this vector.

      Specified by:
      toArray in interface Collection<E>
      Specified by:
      toArray in interface List<E>
      Overrides:
      toArray in class AbstractList<E>

    • toArray

      public <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: the array to fill.
      Returns

      an array of the elements from this vector.

      Throws
      • ArrayStoreException: @throws ArrayStoreException if the type of an element in this vector cannot be stored in the type of the specified array.
      Specified by:
      toArray in interface Collection<E>
      Specified by:
      toArray in interface List<E>
      Overrides:
      toArray in class AbstractList<E>

    • toString

      public String toString()

      Returns the string representation of this vector.

      Returns

      the string representation of this vector.

      See also
      • #elements
      Overrides:
      toString in class AbstractCollection<E>

    • trimToSize

      public void trimToSize()

      Sets the capacity of this vector to be the same as the size.

      See also

      • #capacity

      • #ensureCapacity

      • #size