Java Reference
In-Depth Information
Display 16.7
Methods in the Classes
ArrayList<T>
and
Vector<T>
(part 3 of 4)
public boolean
addAll(Collection<? extends T> c)
Appends all the elements in
c
to the end of the elements in the calling object in the order that they
are enumerated by a
c
iterator. The behavior of this method is not guaranteed if the collection
c
is
the calling object or any collection including the calling object either directly or indirectly.
public boolean
addAll(
int
index, Collection<?
extends
T> c)
Inserts all the elements in
c
into the calling object starting at position
index
. Elements are
inserted in the order that they are enumerated by a
c
iterator. Elements previously at positions
index
or higher are shifted to higher numbered positions.
METHODS TO REMOVE ELEMENTS FOR BOTH
ArrayList<T>
AND
Vector<T>
public
T remove(
int
index)
Deletes the element at the specified index and returns the element deleted. The size of the
calling object is decreased by one. The capacity of the calling object is not changed. Each element
in the calling object with an index greater than or equal to
index
is decreased to have an index
that is one less than the value it had previously.
The
index
must be a value greater than or equal to zero and less than the size of the calling
object (before this removal).
public boolean
remove(Object theElement)
Removes the first occurrence of
theElement
from the calling object. If
theElement
is found
in the calling object, then each element in the calling object with an index greater than or equal to
theElement'
s index is decreased to have an index that is one less than the value it had previously.
Returns
true
if
theElement
was found (and removed). Returns
false
if
theElement
is not found in
the calling object. If the element was removed, the size is decreased by one. The capacity is not changed.
protected void
removeRange(
int
fromIndex,
int
toIndex)
Removes all elements with index greater than or equal to
fromIndex
and strictly less than
toIndex
. Be sure to note that this method is
protected
, not
public
.
public void
clear()
Removes all elements from the calling object and sets its size to zero.
SEARCH METHODS FOR BOTH
ArrayList<T>
AND
Vector<T>
public boolean
isEmpty()
Returns
true
if the calling object is empty (that is, has size
0
); otherwise returns
false
.
public boolean
contains(Object target)
Returns
true
if
target
is an element of the calling object; otherwise returns
false
. Uses the
method equals of the object
target
to test for equality.
public int
indexOf(Object target)
Returns the index of the first element that is equal to
target
. Uses the method
equals
of the
object
target
to test for equality. Returns
1
if
target
is not found.
public int
lastIndexOf(Object target)
Returns the index of the last element that is
equal
to
target
. Uses the method
equals
of the
object
target
to test for equality. Returns
1
if
target
is not found.
(continued)
