Vector (JOSH API Document)

java.lang.Object
- java.util.Vector

Direct Known Subclasses:

Stack
```
public class Vector
extends Object
```
The Vector class implements a growable array of objects. Like an array, it contains components that can be accessed using an integer index. However, the size of a Vector can grow or shrink as needed to accommodate adding and removing items after the Vector has been created.
Each vector tries to optimize storage management by maintaining a capacity and a capacityIncrement. The capacity is always at least as large as the vector size; it is usually larger because as components are added to the vector, the vector's storage increases in chunks the size of capacityIncrement. An application can increase the capacity of a vector before inserting a large number of components; this reduces the amount of incremental reallocation.

Since:

JDK1.0, CLDC 1.0

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`capacityIncrement` The amount by which the capacity of the vector is automatically incremented when its size becomes greater than its capacity.
`protected int`	`elementCount` The number of valid components in the vector.
`protected Object[]`	`elementData` The array buffer into which the components of the vector are stored.

Constructor Summary

Constructors
Constructor and Description
`Vector()` Constructs an empty vector.
`Vector(int initialCapacity)` Constructs an empty vector with the specified initial capacity.
`Vector(int initialCapacity, int capacityIncrement)` Constructs an empty vector with the specified initial capacity and capacity increment.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addElement(Object obj)` Adds the specified component to the end of this vector, increasing its size by one.
`int`	`capacity()` Returns the current capacity of this vector.
`boolean`	`contains(Object elem)` Tests if the specified object is a component in this vector.
`void`	`copyInto(Object[] anArray)` Copies the components of this vector into the specified array.
`Object`	`elementAt(int index)` Returns the component at the specified index.
`Enumeration`	`elements()` Returns an enumeration of the components of this vector.
`void`	`ensureCapacity(int minCapacity)` Increases the capacity of this vector, if necessary, to ensure that it can hold at least the number of components specified by the minimum capacity argument.
`Object`	`firstElement()` Returns the first component of this vector.
`int`	`indexOf(Object elem)` Searches for the first occurrence of the given argument, testing for equality using the `equals` method.
`int`	`indexOf(Object elem, int index)` Searches for the first occurrence of the given argument, beginning the search at `index`, and testing for equality using the `equals` method.
`void`	`insertElementAt(Object obj, int index)` Inserts the specified object as a component in this vector at the specified `index`.
`boolean`	`isEmpty()` Tests if this vector has no components.
`Object`	`lastElement()` Returns the last component of the vector.
`int`	`lastIndexOf(Object elem)` Returns the index of the last occurrence of the specified object in this vector.
`int`	`lastIndexOf(Object elem, int index)` Searches backwards for the specified object, starting from the specified index, and returns an index to it.
`void`	`removeAllElements()` Removes all components from this vector and sets its size to zero.
`boolean`	`removeElement(Object obj)` Removes the first occurrence of the argument from this vector.
`void`	`removeElementAt(int index)` Deletes the component at the specified index.
`void`	`setElementAt(Object obj, int index)` Sets the component at the specified `index` of this vector to be the specified object.
`void`	`setSize(int newSize)` Sets the size of this vector.
`int`	`size()` Returns the number of components in this vector.
`String`	`toString()` Returns a string representation of this vector.
`void`	`trimToSize()` Trims the capacity of this vector to be the vector's current size.

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

- Field Detail
  - elementData
```
protected Object[] elementData
```
    The array buffer into which the components of the vector are stored. The capacity of the vector is the length of this array buffer.
    
    Since:
    
    JDK1.0
  - elementCount
```
protected int elementCount
```
    The number of valid components in the vector.
    
    Since:
    
    JDK1.0
  - capacityIncrement
```
protected int capacityIncrement
```
    The amount by which the capacity of the vector is automatically incremented when its size becomes greater than its capacity. If the capacity increment is 0, the capacity of the vector is doubled each time it needs to grow.
    
    Since:
    
    JDK1.0
- Constructor Detail
  - Vector
```
public Vector(int initialCapacity,
      int capacityIncrement)
```
    Constructs an empty vector with the specified initial capacity and capacity increment.
    
    Parameters:
    initialCapacity - the initial capacity of the vector.
    capacityIncrement - the amount by which the capacity is increased when the vector overflows.
    
    Throws:
    
    IllegalArgumentException - if the specified initial capacity is negative
  - Vector
```
public Vector(int initialCapacity)
```
    Constructs an empty vector with the specified initial capacity.
    
    Parameters:
    initialCapacity - the initial capacity of the vector.
    Since:
    
    JDK1.0
  - Vector
```
public Vector()
```
    Constructs an empty vector.
    
    Since:
    
    JDK1.0
- Method Detail
  - copyInto
```
public void copyInto(Object[] anArray)
```
    Copies the components of this vector into the specified array. The array must be big enough to hold all the objects in this vector.
    
    Parameters:
    anArray - the array into which the components get copied.
    Since:
    
    JDK1.0
  - trimToSize
```
public void trimToSize()
```
    Trims the capacity of this vector to be the vector's current size. An application can use this operation to minimize the storage of a vector.
    
    Since:
    
    JDK1.0
  - ensureCapacity
```
public void ensureCapacity(int minCapacity)
```
    Increases the capacity of this vector, if necessary, to ensure that it can hold at least the number of components specified by the minimum capacity argument.
    
    Parameters:
    minCapacity - the desired minimum capacity.
    Since:
    
    JDK1.0
  - setSize
```
public void setSize(int newSize)
```
    Sets the size of this vector. If the new size is greater than the current size, new null items are added to the end of the vector. If the new size is less than the current size, all components at index newSize and greater are discarded.
    
    Parameters:
    newSize - the new size of this vector.
    
    Throws:
    
    ArrayIndexOutOfBoundsException - if new size is negative.
    Since:
    
    JDK1.0
  - capacity
```
public int capacity()
```
    Returns the current capacity of this vector.
    
    Returns:
    the current capacity of this vector.
    Since:
    
    JDK1.0
  - size
```
public int size()
```
    Returns the number of components in this vector.
    
    Returns:
    the number of components in this vector.
    Since:
    
    JDK1.0
  - isEmpty
```
public boolean isEmpty()
```
    Tests if this vector has no components.
    
    Returns:
    true if this vector has no components; false otherwise.
    Since:
    
    JDK1.0
  - elements
```
public Enumeration elements()
```
    Returns an enumeration of the components of this vector.
    
    Returns:
    an enumeration of the components of this vector.
    Since:
    
    JDK1.0
    
    See Also:
    Enumeration
  - contains
```
public boolean contains(Object elem)
```
    Tests if the specified object is a component in this vector.
    
    Parameters:
    elem - an object.
    
    Returns:
    true if the specified object is a component in this vector; false otherwise.
    Since:
    
    JDK1.0
  - indexOf
```
public int indexOf(Object elem)
```
    Searches for the first occurrence of the given argument, testing for equality using the equals method.
    
    Parameters:
    elem - an object.
    
    Returns:
    the index of the first occurrence of the argument in this vector; returns -1 if the object is not found.
    Since:
    
    JDK1.0
    
    See Also:
    Object.equals(java.lang.Object)
  - indexOf
```
public int indexOf(Object elem,
          int index)
```
    Searches for the first occurrence of the given argument, beginning the search at index, and testing for equality using the equals method.
    
    Parameters:
    elem - an object.
    index - the index to start searching from.
    
    Returns:
    the index of the first occurrence of the object argument in this vector at position index or later in the vector; returns -1 if the object is not found.
    Since:
    
    JDK1.0
    
    See Also:
    Object.equals(java.lang.Object)
  - lastIndexOf
```
public int lastIndexOf(Object elem)
```
    Returns the index of the last occurrence of the specified object in this vector.
    
    Parameters:
    elem - the desired component.
    
    Returns:
    the index of the last occurrence of the specified object in this vector; returns -1 if the object is not found.
    Since:
    
    JDK1.0
  - lastIndexOf
```
public int lastIndexOf(Object elem,
              int index)
```
    Searches backwards for the specified object, starting from the specified index, and returns an index to it.
    
    Parameters:
    elem - the desired component.
    index - the index to start searching from.
    
    Returns:
    the index of the last occurrence of the specified object in this vector at position less than index in the vector; -1 if the object is not found.
    
    Throws:
    
    IndexOutOfBoundsException - if index is greater than or equal to the current size of this vector.
    Since:
    
    JDK1.0
  - elementAt
```
public Object elementAt(int index)
```
    Returns the component at the specified index.
    
    Parameters:
    index - an index into this vector.
    
    Returns:
    the component at the specified index.
    
    Throws:
    
    ArrayIndexOutOfBoundsException - if an invalid index was given.
    Since:
    
    JDK1.0
  - firstElement
```
public Object firstElement()
```
    Returns the first component of this vector.
    
    Returns:
    the first component of this vector.
    
    Throws:
    
    NoSuchElementException - if this vector has no components.
    Since:
    
    JDK1.0
  - lastElement
```
public Object lastElement()
```
    Returns the last component of the vector.
    
    Returns:
    the last component of the vector, i.e., the component at index size() - 1.
    
    Throws:
    
    NoSuchElementException - if this vector is empty.
    Since:
    
    JDK1.0
  - setElementAt
```
public void setElementAt(Object obj,
                int index)
```
    Sets the component at the specified index of this vector to be the specified object. The previous component at that position is discarded.
    The index must be a value greater than or equal to 0 and less than the current size of the vector.
    
    Parameters:
    obj - what the component is to be set to.
    index - the specified index.
    
    Throws:
    
    ArrayIndexOutOfBoundsException - if the index was invalid.
    Since:
    
    JDK1.0
    
    See Also:
    size()
  - removeElementAt
```
public void removeElementAt(int index)
```
    Deletes the component at the specified index. Each component in this vector with an index greater or equal to the specified index is shifted downward to have an index one smaller than the value it had previously.
    The index must be a value greater than or equal to 0 and less than the current size of the vector.
    
    Parameters:
    index - the index of the object to remove.
    
    Throws:
    
    ArrayIndexOutOfBoundsException - if the index was invalid.
    Since:
    
    JDK1.0
    
    See Also:
    size()
  - insertElementAt
```
public void insertElementAt(Object obj,
                   int index)
```
    Inserts the specified object as a component in this vector at the specified index. Each component in this vector with an index greater or equal to the specified index is shifted upward to have an index one greater than the value it had previously.
    The index must be a value greater than or equal to 0 and less than or equal to the current size of the vector.
    
    Parameters:
    obj - the component to insert.
    index - where to insert the new component.
    
    Throws:
    
    ArrayIndexOutOfBoundsException - if the index was invalid.
    Since:
    
    JDK1.0
    
    See Also:
    size()
  - addElement
```
public void addElement(Object obj)
```
    Adds the specified component to the end of this vector, increasing its size by one. The capacity of this vector is increased if its size becomes greater than its capacity.
    
    Parameters:
    obj - the component to be added.
    Since:
    
    JDK1.0
  - removeElement
```
public boolean removeElement(Object obj)
```
    Removes the first occurrence of the argument from this vector. If the object is found in this vector, each component in the vector with an index greater or equal to the object's index is shifted downward to have an index one smaller than the value it had previously.
    
    Parameters:
    obj - the component to be removed.
    
    Returns:
    true if the argument was a component of this vector; false otherwise.
    Since:
    
    JDK1.0
  - removeAllElements
```
public void removeAllElements()
```
    Removes all components from this vector and sets its size to zero.
    
    Since:
    
    JDK1.0
  - toString
```
public String toString()
```
    Returns a string representation of this vector.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    a string representation of this vector.
    Since:
    
    JDK1.0

Class Vector

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

elementData

elementCount

capacityIncrement

Constructor Detail

Vector

Vector

Vector

Method Detail

copyInto

trimToSize

ensureCapacity

setSize

capacity

size

isEmpty

elements

contains

indexOf

indexOf

lastIndexOf

lastIndexOf

elementAt

firstElement

lastElement

setElementAt

removeElementAt

insertElementAt

addElement

removeElement

removeAllElements

toString