Appends the specified element to the end of this list.
This method is equivalent to addLast.
e | element to be appended to this list |
true (as specified by Collection.add)
Inserts the specified element at the specified position in this list. Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices).
index | index at which the specified element is to be inserted | |
element | element to be inserted |
Appends all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified collection's iterator. The behavior of this operation is undefined if the specified collection is modified while the operation is in progress. (Note that this will occur if the specified collection is this list, and it's nonempty.)
c | collection containing elements to be added to this list |
true if this list changed as a result of the call
Inserts all of the elements in the specified collection into this list, starting at the specified position. Shifts the element currently at that position (if any) and any subsequent elements to the right (increases their indices). The new elements will appear in the list in the order that they are returned by the specified collection's iterator.
index | index at which to insert the first element from the specified collection | |
c | collection containing elements to be added to this list |
true if this list changed as a result of the call
Inserts the specified element at the beginning of this list.
e | the element to add |
Appends the specified element to the end of this list.
This method is equivalent to add.
e | the element to add |
Removes all of the elements from this list. The list will be empty after this call returns.
Returns true if this list contains the specified element.
More formally, returns true if and only if this list contains
at least one element e such that
(o==null ? e==null : o.equals(e)).
o | element whose presence in this list is to be tested |
true if this list contains the specified element
Returns an iterator over the elements in this deque in reverse sequential order. The elements will be returned in order from last (tail) to first (head).
Retrieves, but does not remove, the head (first element) of this list.
Returns the element at the specified position in this list.
index | index of the element to return |
Returns the first element in this list.
Returns the last element in this list.
Returns the index of the first occurrence of the specified element
in this list, or -1 if this list does not contain the element.
More formally, returns the lowest index i such that
(o==null ? get(i)==null : o.equals(get(i))),
or -1 if there is no such index.
o | element to search for |
Returns the index of the last occurrence of the specified element
in this list, or -1 if this list does not contain the element.
More formally, returns the highest index i such that
(o==null ? get(i)==null : o.equals(get(i))),
or -1 if there is no such index.
o | element to search for |
Returns a list-iterator of the elements in this list (in proper
sequence), starting at the specified position in the list.
Obeys the general contract of List.listIterator(int).
The list-iterator is fail-fast: if the list is structurally
modified at any time after the Iterator is created, in any way except
through the list-iterator's own remove or add
methods, the list-iterator will throw a
ConcurrentModificationException. Thus, in the face of
concurrent modification, the iterator fails quickly and cleanly, rather
than risking arbitrary, non-deterministic behavior at an undetermined
time in the future.
index | index of the first element to be returned from the
list-iterator (by a call to next) |
List.listIterator(int)
Adds the specified element as the tail (last element) of this list.
e | the element to add |
true (as specified by Queue.offer)
Inserts the specified element at the front of this list.
e | the element to insert |
true (as specified by Deque.offerFirst)
Inserts the specified element at the end of this list.
e | the element to insert |
true (as specified by Deque.offerLast)
Retrieves, but does not remove, the head (first element) of this list.
null if this list is empty
Retrieves, but does not remove, the first element of this list,
or returns null if this list is empty.
null
if this list is empty
Retrieves, but does not remove, the last element of this list,
or returns null if this list is empty.
null
if this list is empty
Retrieves and removes the head (first element) of this list.
null if this list is empty
Retrieves and removes the first element of this list,
or returns null if this list is empty.
null if
this list is empty
Retrieves and removes the last element of this list,
or returns null if this list is empty.
null if
this list is empty
Pops an element from the stack represented by this list. In other words, removes and returns the first element of this list.
This method is equivalent to removeFirst().
Pushes an element onto the stack represented by this list. In other words, inserts the element at the front of this list.
This method is equivalent to addFirst.
e | the element to push |
Retrieves and removes the head (first element) of this list.
Removes the first occurrence of the specified element from this list,
if it is present. If this list does not contain the element, it is
unchanged. More formally, removes the element with the lowest index
i such that
(o==null ? get(i)==null : o.equals(get(i)))
(if such an element exists). Returns true if this list
contained the specified element (or equivalently, if this list
changed as a result of the call).
o | element to be removed from this list, if present |
true if this list contained the specified element
Removes the element at the specified position in this list. Shifts any subsequent elements to the left (subtracts one from their indices). Returns the element that was removed from the list.
index | the index of the element to be removed |
Removes and returns the first element from this list.
Removes the first occurrence of the specified element in this list (when traversing the list from head to tail). If the list does not contain the element, it is unchanged.
o | element to be removed from this list, if present |
true if the list contained the specified element
Removes and returns the last element from this list.
Removes the last occurrence of the specified element in this list (when traversing the list from head to tail). If the list does not contain the element, it is unchanged.
o | element to be removed from this list, if present |
true if the list contained the specified element
Replaces the element at the specified position in this list with the specified element.
index | index of the element to replace | |
element | element to be stored at the specified position |
Returns the number of elements in this list.
Creates a late-binding
and fail-fast Spliterator over the elements in this
list.
The Spliterator reports Spliterator.SIZED and
Spliterator.ORDERED. Overriding implementations should document
the reporting of additional characteristic values.
Spliterator over the elements in this list
@implNote
The Spliterator additionally reports Spliterator.SUBSIZED
and implements trySplit to permit limited parallelism..
Returns an array containing all of the elements in this list in proper sequence (from first to last element).
The returned array will be "safe" in that no references to it are maintained by this list. (In other words, this method must allocate a new array). The caller is thus free to modify the returned array.
This method acts as bridge between array-based and collection-based APIs.
Returns an array containing all of the elements in this list in proper sequence (from first to last element); the runtime type of the returned array is that of the specified array. If the list fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this list.
If the list fits in the specified array with room to spare (i.e.,
the array has more elements than the list), the element in the array
immediately following the end of the list is set to null.
(This is useful in determining the length of the list only if
the caller knows that the list does not contain any null elements.)
Like the toArray() method, this method acts as bridge between
array-based and collection-based APIs. Further, this method allows
precise control over the runtime type of the output array, and may,
under certain circumstances, be used to save allocation costs.
Suppose x is a list known to contain only strings.
The following code can be used to dump the list into a newly
allocated array of String:
String[] y = x.toArray(new String[0]);
Note that toArray(new Object[0]) is identical in function to
toArray().
a | the array into which the elements of the list are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose. |
Diagram: Collection List