Module java.base
Package java.util

# Interface List<E>

Type Parameters:
  `E` - the type of elements in this list

All Superinterfaces:
  `Collection<E>`, `Iterable<E>`, `SequencedCollection<E>`

All Known Implementing Classes:
  `AbstractList`, `AbstractSequentialList`, `ArrayList`, `AttributeList`, `CopyOnWriteArrayList`, `LinkedList`, `RoleList`, `RoleUnresolvedList`, `Stack`, `Vector`

public interface List<E> extends SequencedCollection<E>
An ordered collection, where the user has precise control over where in the list each element is inserted. The user can access elements by their integer index (position in the list), and search for elements in the list.

Unlike sets, lists typically allow duplicate elements. More formally, lists typically allow pairs of elements `e1` and `e2` such that `e1.equals(e2)`, and they typically allow multiple null elements if they allow null elements at all. It is not inconceivable that someone might wish to implement a list that prohibits duplicates, by throwing runtime exceptions when the user attempts to insert them, but we expect this usage to be rare.

The `List` interface places additional stipulations, beyond those specified in the `Collection` interface, on the contracts of the `iterator`, `add`, `remove`, `equals`, and `hashCode` methods. Declarations for other inherited methods are also included here for convenience.

The `List` interface provides four methods for positional (indexed) access to list elements. Lists (like Java arrays) are zero based. Note that these operations may execute in time proportional to the index value for some implementations (the `LinkedList` class, for example). Thus, iterating over the elements in a list is typically preferable to indexing through it if the caller does not know the implementation.

The `List` interface provides a special iterator, called a `ListIterator`, that allows element insertion and replacement, and bidirectional access in addition to the normal operations that the `Iterator` interface provides. A method is provided to obtain a list iterator that starts at a specified position in the list.

The `List` interface provides two methods to search for a specified object. From a performance standpoint, these methods should be used with caution. In many implementations they will perform costly linear searches.

The `List` interface provides two methods to efficiently insert and remove multiple elements at an arbitrary point in the list.

Note: While it is permissible for lists to contain themselves as elements, extreme caution is advised: the `equals` and `hashCode` methods are no longer well defined on such a list.

Some list implementations have restrictions on the elements that they may contain. For example, some implementations prohibit null elements, and some have restrictions on the types of their elements. Attempting to add an ineligible element throws an unchecked exception, typically `NullPointerException` or `ClassCastException`. Attempting to query the presence of an ineligible element may throw an exception, or it may simply return false; some implementations will exhibit the former behavior and some will exhibit the latter. More generally, attempting an operation on an ineligible element whose completion would not result in the insertion of an ineligible element into the list may throw an exception or it may succeed, at the option of the implementation. Such exceptions are marked as "optional" in the specification for this interface.

## Unmodifiable Lists

The `List.of` and `List.copyOf` static factory methods provide a convenient way to create unmodifiable lists. The `List` instances created by these methods have the following characteristics:

- They are unmodifiable. Elements cannot be added, removed, or replaced. Calling any mutator method on the List will always cause `UnsupportedOperationException` to be thrown. However, if the contained elements are themselves mutable, this may cause the List's contents to appear to change.
- They disallow `null` elements. Attempts to create them with `null` elements result in `NullPointerException`.
- They are serializable if all elements are serializable.
- The order of elements in the list is the same as the order of the provided arguments, or of the elements in the provided array.
- The lists and their `subList` views implement the `RandomAccess` interface.
- They are value-based. Programmers should treat instances that are equal as interchangeable and should not use them for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail. Callers should make no assumptions about the identity of the returned instances. Factories are free to create new instances or reuse existing ones.
- They are serialized as specified on the Serialized Form page.

This interface is a member of the Java Collections Framework.

Since:
  1.2
See Also:
  - `Collection`
  - `Set`
  - `ArrayList`
  - `LinkedList`
  - `Vector`
  - `Arrays.asList(Object[])`
  - `Collections.nCopies(int, Object)`
  - `Collections.EMPTY_LIST`
  - `AbstractList`
  - `AbstractSequentialList`

## Method Summary

Modifier and Type
Method
Description
`void`
`add(int index, E element)`
Inserts the specified element at the specified position in this list (optional operation).
`boolean`
`add(E e)`
Appends the specified element to the end of this list (optional operation).
`boolean`
`addAll(int index, Collection<? extends E> c)`
Inserts all of the elements in the specified collection into this list at the specified position (optional operation).
`boolean`
`addAll(Collection<? extends E> c)`
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 (optional operation).
`default void`
`addFirst(E e)`
Adds an element as the first element of this collection (optional operation).
`default void`
`addLast(E e)`
Adds an element as the last element of this collection (optional operation).
`void`
`clear()`
Removes all of the elements from this list (optional operation).
`boolean`
`contains(Object o)`
Returns `true` if this list contains the specified element.
`boolean`
`containsAll(Collection<?> c)`
Returns `true` if this list contains all of the elements of the specified collection.
`static <E> List<E>`
`copyOf(Collection<? extends E> coll)`
Returns an unmodifiable List containing the elements of the given Collection, in its iteration order.
`boolean`
`equals(Object o)`
Compares the specified object with this list for equality.
`E`
`get(int index)`
Returns the element at the specified position in this list.
`default E`
`getFirst()`
Gets the first element of this collection.
`default E`
`getLast()`
Gets the last element of this collection.
`int`
`hashCode()`
Returns the hash code value for this list.
`int`
`indexOf(Object o)`
Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.
`boolean`
`isEmpty()`
Returns `true` if this list contains no elements.
`Iterator<E>`
`iterator()`
Returns an iterator over the elements in this list in proper sequence.
`int`
`lastIndexOf(Object o)`
Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.
`ListIterator<E>`
`listIterator()`
Returns a list iterator over the elements in this list (in proper sequence).
`ListIterator<E>`
`listIterator(int index)`
Returns a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list.
`static <E> List<E>`
`of()`
Returns an unmodifiable list containing zero elements.
`static <E> List<E>`
`of(E e1)`
Returns an unmodifiable list containing one element.
`static <E> List<E>`
`of(E... elements)`
Returns an unmodifiable list containing an arbitrary number of elements.
`static <E> List<E>`
`of(E e1, E e2)`
Returns an unmodifiable list containing two elements.
`static <E> List<E>`
`of(E e1, E e2, E e3)`
Returns an unmodifiable list containing three elements.
`static <E> List<E>`
`of(E e1, E e2, E e3, E e4)`
Returns an unmodifiable list containing four elements.
`static <E> List<E>`
`of(E e1, E e2, E e3, E e4, E e5)`
Returns an unmodifiable list containing five elements.
`static <E> List<E>`
`of(E e1, E e2, E e3, E e4, E e5, E e6)`
Returns an unmodifiable list containing six elements.
`static <E> List<E>`
`of(E e1, E e2, E e3, E e4, E e5, E e6, E e7)`
Returns an unmodifiable list containing seven elements.
`static <E> List<E>`
`of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8)`
Returns an unmodifiable list containing eight elements.
`static <E> List<E>`
`of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9)`
Returns an unmodifiable list containing nine elements.
`static <E> List<E>`
`of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9, E e10)`
Returns an unmodifiable list containing ten elements.
`E`
`remove(int index)`
Removes the element at the specified position in this list (optional operation).
`boolean`
`remove(Object o)`
Removes the first occurrence of the specified element from this list, if it is present (optional operation).
`boolean`
`removeAll(Collection<?> c)`
Removes from this list all of its elements that are contained in the specified collection (optional operation).
`default E`
`removeFirst()`
Removes and returns the first element of this collection (optional operation).
`default E`
`removeLast()`
Removes and returns the last element of this collection (optional operation).
`default void`
`replaceAll(UnaryOperator<E> operator)`
Replaces each element of this list with the result of applying the operator to that element.
`boolean`
`retainAll(Collection<?> c)`
Retains only the elements in this list that are contained in the specified collection (optional operation).
`default List<E>`
`reversed()`
Returns a reverse-ordered view of this collection.
`E`
`set(int index, E element)`
Replaces the element at the specified position in this list with the specified element (optional operation).
`int`
`size()`
Returns the number of elements in this list.
`default void`
`sort(Comparator<? super E> c)`
Sorts this list according to the order induced by the specified `Comparator`.
`default Spliterator<E>`
`spliterator()`
Creates a `Spliterator` over the elements in this list.
`List<E>`
`subList(int fromIndex, int toIndex)`
Returns a view of the portion of this list between the specified `fromIndex`, inclusive, and `toIndex`, exclusive.
`Object[]`
`toArray()`
Returns an array containing all of the elements in this list in proper sequence (from first to last element).
`<T> T[]`
`toArray(T[] a)`
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.

### Methods declared in interface java.util.Collection

`parallelStream, removeIf, stream, toArray`

### Methods declared in interface java.lang.Iterable

`forEach`

## Method Details

### size

int size()
Returns the number of elements in this list. If this list contains more than `Integer.MAX_VALUE` elements, returns `Integer.MAX_VALUE`.

Specified by:
  `size` in interface `Collection<E>`
Returns:
  the number of elements in this list

### isEmpty

boolean isEmpty()
Returns `true` if this list contains no elements.

Specified by:
  `isEmpty` in interface `Collection<E>`
Returns:
  `true` if this list contains no elements

### contains

boolean contains(Object o)
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 `Objects.equals(o, e)`.

Specified by:
  `contains` in interface `Collection<E>`
Parameters:
  `o` - element whose presence in this list is to be tested
Returns:
  `true` if this list contains the specified element
Throws:
  `ClassCastException` - if the type of the specified element is incompatible with this list (optional)
  `NullPointerException` - if the specified element is null and this list does not permit null elements (optional)

### iterator

Iterator<E> iterator()
Returns an iterator over the elements in this list in proper sequence.

Specified by:
  `iterator` in interface `Collection<E>`
Specified by:
  `iterator` in interface `Iterable<E>`
Returns:
  an iterator over the elements in this list in proper sequence

### toArray

Object[] toArray()
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 even if this list is backed by an array). The caller is thus free to modify the returned array.

This method acts as bridge between array-based and collection-based APIs.

Specified by:
  `toArray` in interface `Collection<E>`
Returns:
  an array containing all of the elements in this list in proper sequence
See Also:
  - `Arrays.asList(Object[])`

### toArray

<T> T[] toArray(T[] a)
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()`.

Specified by:
  `toArray` in interface `Collection<E>`
Type Parameters:
  `T` - the component type of the array to contain the collection
Parameters:
  `a` - the array into which the elements of this list are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose.
Returns:
  an array containing the elements of this list
Throws:
  `ArrayStoreException` - if the runtime type of the specified array is not a supertype of the runtime type of every element in this list
  `NullPointerException` - if the specified array is null

### add

boolean add(E e)
Appends the specified element to the end of this list (optional operation).

Lists that support this operation may place limitations on what elements may be added to this list. In particular, some lists will refuse to add null elements, and others will impose restrictions on the type of elements that may be added. List classes should clearly specify in their documentation any restrictions on what elements may be added.

Specified by:
  `add` in interface `Collection<E>`
Parameters:
  `e` - element to be appended to this list
Returns:
  `true` (as specified by `Collection.add(E)`)
Throws:
  `UnsupportedOperationException` - if the `add` operation is not supported by this list
  `ClassCastException` - if the class of the specified element prevents it from being added to this list
  `NullPointerException` - if the specified element is null and this list does not permit null elements
  `IllegalArgumentException` - if some property of this element prevents it from being added to this list

### remove

boolean remove(Object o)
Removes the first occurrence of the specified element from this list, if it is present (optional operation). If this list does not contain the element, it is unchanged. More formally, removes the element with the lowest index `i` such that `Objects.equals(o, 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).

Specified by:
  `remove` in interface `Collection<E>`
Parameters:
  `o` - element to be removed from this list, if present
Returns:
  `true` if this list contained the specified element
Throws:
  `ClassCastException` - if the type of the specified element is incompatible with this list (optional)
  `NullPointerException` - if the specified element is null and this list does not permit null elements (optional)
  `UnsupportedOperationException` - if the `remove` operation is not supported by this list

### containsAll

boolean containsAll(Collection<?> c)
Returns `true` if this list contains all of the elements of the specified collection.

Specified by:
  `containsAll` in interface `Collection<E>`
Parameters:
  `c` - collection to be checked for containment in this list
Returns:
  `true` if this list contains all of the elements of the specified collection
Throws:
  `ClassCastException` - if the types of one or more elements in the specified collection are incompatible with this list (optional)
  `NullPointerException` - if the specified collection contains one or more null elements and this list does not permit null elements (optional), or if the specified collection is null
See Also:
  - `contains(Object)`

### addAll

boolean addAll(Collection<? extends E> c)
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 (optional operation). 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.)

Specified by:
  `addAll` in interface `Collection<E>`
Parameters:
  `c` - collection containing elements to be added to this list
Returns:
  `true` if this list changed as a result of the call
Throws:
  `UnsupportedOperationException` - if the `addAll` operation is not supported by this list
  `ClassCastException` - if the class of an element of the specified collection prevents it from being added to this list
  `NullPointerException` - if the specified collection contains one or more null elements and this list does not permit null elements, or if the specified collection is null
  `IllegalArgumentException` - if some property of an element of the specified collection prevents it from being added to this list
See Also:
  - `add(Object)`

### addAll

boolean addAll(int index, Collection<? extends E> c)
Inserts all of the elements in the specified collection into this list at the specified position (optional operation). 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 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.)

Parameters:
  `index` - index at which to insert the first element from the specified collection
  `c` - collection containing elements to be added to this list
Returns:
  `true` if this list changed as a result of the call
Throws:
  `UnsupportedOperationException` - if the `addAll` operation is not supported by this list
  `ClassCastException` - if the class of an element of the specified collection prevents it from being added to this list
  `NullPointerException` - if the specified collection contains one or more null elements and this list does not permit null elements, or if the specified collection is null
  `IllegalArgumentException` - if some property of an element of the specified collection prevents it from being added to this list
  `IndexOutOfBoundsException` - if the index is out of range (`index < 0 || index > size()`)

### removeAll

boolean removeAll(Collection<?> c)
Removes from this list all of its elements that are contained in the specified collection (optional operation).

Specified by:
  `removeAll` in interface `Collection<E>`
Parameters:
  `c` - collection containing elements to be removed from this list
Returns:
  `true` if this list changed as a result of the call
Throws:
  `UnsupportedOperationException` - if the `removeAll` operation is not supported by this list
  `ClassCastException` - if the class of an element of this list is incompatible with the specified collection (optional)
  `NullPointerException` - if this list contains a null element and the specified collection does not permit null elements (optional), or if the specified collection is null
See Also:
  - `remove(Object)`
  - `contains(Object)`

### retainAll

boolean retainAll(Collection<?> c)
Retains only the elements in this list that are contained in the specified collection (optional operation). In other words, removes from this list all of its elements that are not contained in the specified collection.

Specified by:
  `retainAll` in interface `Collection<E>`
Parameters:
  `c` - collection containing elements to be retained in this list
Returns:
  `true` if this list changed as a result of the call
Throws:
  `UnsupportedOperationException` - if the `retainAll` operation is not supported by this list
  `ClassCastException` - if the class of an element of this list is incompatible with the specified collection (optional)
  `NullPointerException` - if this list contains a null element and the specified collection does not permit null elements (optional), or if the specified collection is null
See Also:
  - `remove(Object)`
  - `contains(Object)`

### replaceAll

default void replaceAll(UnaryOperator<E> operator)
Replaces each element of this list with the result of applying the operator to that element. Errors or runtime exceptions thrown by the operator are relayed to the caller.

Implementation Requirements:
  The default implementation is equivalent to, for this `list`:

           final ListIterator<E> li = list.listIterator();
           while (li.hasNext()) {
               li.set(operator.apply(li.next()));
           }

  If the list's list-iterator does not support the `set` operation then an `UnsupportedOperationException` will be thrown when replacing the first element.
Parameters:
  `operator` - the operator to apply to each element
Throws:
  `UnsupportedOperationException` - if this list is unmodifiable. Implementations may throw this exception if an element cannot be replaced or if, in general, modification is not supported
  `NullPointerException` - if the specified operator is null or if the operator result is a null value and this list does not permit null elements (optional)
Since:
  1.8

### sort

default void sort(Comparator<? super E> c)
Sorts this list according to the order induced by the specified `Comparator`. The sort is stable: this method must not reorder equal elements.

All elements in this list must be mutually comparable using the specified comparator (that is, `c.compare(e1, e2)` must not throw a `ClassCastException` for any elements `e1` and `e2` in the list).

If the specified comparator is `null` then all elements in this list must implement the `Comparable` interface and the elements' natural ordering should be used.

This list must be modifiable, but need not be resizable.

Implementation Requirements:
  The default implementation obtains an array containing all elements in this list, sorts the array, and iterates over this list resetting each element from the corresponding position in the array. (This avoids the n2 log(n) performance that would result from attempting to sort a linked list in place.)
Implementation Note:
  This implementation is a stable, adaptive, iterative mergesort that requires far fewer than n lg(n) comparisons when the input array is partially sorted, while offering the performance of a traditional mergesort when the input array is randomly ordered. If the input array is nearly sorted, the implementation requires approximately n comparisons. Temporary storage requirements vary from a small constant for nearly sorted input arrays to n/2 object references for randomly ordered input arrays.

  The implementation takes equal advantage of ascending and descending order in its input array, and can take advantage of ascending and descending order in different parts of the same input array. It is well-suited to merging two or more sorted arrays: simply concatenate the arrays and sort the resulting array.

  The implementation was adapted from Tim Peters's list sort for Python ( TimSort). It uses techniques from Peter McIlroy's "Optimistic Sorting and Information Theoretic Complexity", in Proceedings of the Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474, January 1993.

Parameters:
  `c` - the `Comparator` used to compare list elements. A `null` value indicates that the elements' natural ordering should be used
Throws:
  `ClassCastException` - if the list contains elements that are not mutually comparable using the specified comparator
  `UnsupportedOperationException` - if the list's list-iterator does not support the `set` operation
  `IllegalArgumentException` - (optional) if the comparator is found to violate the `Comparator` contract
Since:
  1.8

### clear

void clear()
Removes all of the elements from this list (optional operation). The list will be empty after this call returns.

Specified by:
  `clear` in interface `Collection<E>`
Throws:
  `UnsupportedOperationException` - if the `clear` operation is not supported by this list

### equals

boolean equals(Object o)
Compares the specified object with this list for equality. Returns `true` if and only if the specified object is also a list, both lists have the same size, and all corresponding pairs of elements in the two lists are equal. (Two elements `e1` and `e2` are equal if `Objects.equals(e1, e2)`.) In other words, two lists are defined to be equal if they contain the same elements in the same order. This definition ensures that the equals method works properly across different implementations of the `List` interface.

Specified by:
  `equals` in interface `Collection<E>`
Overrides:
  `equals` in class `Object`
Parameters:
  `o` - the object to be compared for equality with this list
Returns:
  `true` if the specified object is equal to this list
See Also:
  - `Object.hashCode()`
  - `HashMap`

### hashCode

int hashCode()
Returns the hash code value for this list. The hash code of a list is defined to be the result of the following calculation:

         int hashCode = 1;
         for (E e : list)
             hashCode = 31*hashCode + (e==null ? 0 : e.hashCode());

This ensures that `list1.equals(list2)` implies that `list1.hashCode()==list2.hashCode()` for any two lists, `list1` and `list2`, as required by the general contract of `Object.hashCode()`.

Specified by:
  `hashCode` in interface `Collection<E>`
Overrides:
  `hashCode` in class `Object`
Returns:
  the hash code value for this list
See Also:
  - `Object.equals(Object)`
  - `equals(Object)`

### get

E get(int index)
Returns the element at the specified position in this list.

Parameters:
  `index` - index of the element to return
Returns:
  the element at the specified position in this list
Throws:
  `IndexOutOfBoundsException` - if the index is out of range (`index < 0 || index >= size()`)

### set

E set(int index, E element)
Replaces the element at the specified position in this list with the specified element (optional operation).

Parameters:
  `index` - index of the element to replace
  `element` - element to be stored at the specified position
Returns:
  the element previously at the specified position
Throws:
  `UnsupportedOperationException` - if the `set` operation is not supported by this list
  `ClassCastException` - if the class of the specified element prevents it from being added to this list
  `NullPointerException` - if the specified element is null and this list does not permit null elements
  `IllegalArgumentException` - if some property of the specified element prevents it from being added to this list
  `IndexOutOfBoundsException` - if the index is out of range (`index < 0 || index >= size()`)

### add

void add(int index, E element)
Inserts the specified element at the specified position in this list (optional operation). Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices).

Parameters:
  `index` - index at which the specified element is to be inserted
  `element` - element to be inserted
Throws:
  `UnsupportedOperationException` - if the `add` operation is not supported by this list
  `ClassCastException` - if the class of the specified element prevents it from being added to this list
  `NullPointerException` - if the specified element is null and this list does not permit null elements
  `IllegalArgumentException` - if some property of the specified element prevents it from being added to this list
  `IndexOutOfBoundsException` - if the index is out of range (`index < 0 || index > size()`)

### remove

E remove(int index)
Removes the element at the specified position in this list (optional operation). Shifts any subsequent elements to the left (subtracts one from their indices). Returns the element that was removed from the list.

Parameters:
  `index` - the index of the element to be removed
Returns:
  the element previously at the specified position
Throws:
  `UnsupportedOperationException` - if the `remove` operation is not supported by this list
  `IndexOutOfBoundsException` - if the index is out of range (`index < 0 || index >= size()`)

### indexOf

int indexOf(Object o)
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 `Objects.equals(o, get(i))`, or -1 if there is no such index.

Parameters:
  `o` - element to search for
Returns:
  the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element
Throws:
  `ClassCastException` - if the type of the specified element is incompatible with this list (optional)
  `NullPointerException` - if the specified element is null and this list does not permit null elements (optional)

### lastIndexOf

int lastIndexOf(Object o)
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 `Objects.equals(o, get(i))`, or -1 if there is no such index.

Parameters:
  `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
Throws:
  `ClassCastException` - if the type of the specified element is incompatible with this list (optional)
  `NullPointerException` - if the specified element is null and this list does not permit null elements (optional)

### listIterator

ListIterator<E> listIterator()
Returns a list iterator over the elements in this list (in proper sequence).

Returns:
  a list iterator over the elements in this list (in proper sequence)

### listIterator

ListIterator<E> listIterator(int index)
Returns a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list. The specified index indicates the first element that would be returned by an initial call to `next`. An initial call to `previous` would return the element with the specified index minus one.

Parameters:
  `index` - index of the first element to be returned from the list iterator (by a call to `next`)
Returns:
  a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list
Throws:
  `IndexOutOfBoundsException` - if the index is out of range (`index < 0 || index > size()`)

### subList

List<E> subList(int fromIndex, int toIndex)
Returns a view of the portion of this list between the specified `fromIndex`, inclusive, and `toIndex`, exclusive. (If `fromIndex` and `toIndex` are equal, the returned list is empty.) The returned list is backed by this list, so non-structural changes in the returned list are reflected in this list, and vice-versa. The returned list supports all of the optional list operations supported by this list.

This method eliminates the need for explicit range operations (of the sort that commonly exist for arrays). Any operation that expects a list can be used as a range operation by passing a subList view instead of a whole list. For example, the following idiom removes a range of elements from a list:

          list.subList(from, to).clear();

Similar idioms may be constructed for `indexOf` and `lastIndexOf`, and all of the algorithms in the `Collections` class can be applied to a subList.

The semantics of the list returned by this method become undefined if the backing list (i.e., this list) is structurally modified in any way other than via the returned list. (Structural modifications are those that change the size of this list, or otherwise perturb it in such a fashion that iterations in progress may yield incorrect results.)

Parameters:
  `fromIndex` - low endpoint (inclusive) of the subList
  `toIndex` - high endpoint (exclusive) of the subList
Returns:
  a view of the specified range within this list
Throws:
  `IndexOutOfBoundsException` - for an illegal endpoint index value (`fromIndex < 0 || toIndex > size || fromIndex > toIndex`)

### spliterator

default Spliterator<E> spliterator()
Creates a `Spliterator` over the elements in this list.

The `Spliterator` reports `Spliterator.SIZED` and `Spliterator.ORDERED`. Implementations should document the reporting of additional characteristic values.

Specified by:
  `spliterator` in interface `Collection<E>`
Specified by:
  `spliterator` in interface `Iterable<E>`
Implementation Requirements:
  The default implementation creates a late-binding spliterator as follows:
  - If the list is an instance of `RandomAccess` then the default implementation creates a spliterator that traverses elements by invoking the method `get(int)`. If such invocation results or would result in an `IndexOutOfBoundsException` then the spliterator will fail-fast and throw a `ConcurrentModificationException`. If the list is also an instance of `AbstractList` then the spliterator will use the list's `modCount` field to provide additional fail-fast behavior.
  - Otherwise, the default implementation creates a spliterator from the list's `Iterator`. The spliterator inherits the fail-fast of the list's iterator.
Implementation Note:
  The created `Spliterator` additionally reports `Spliterator.SUBSIZED`.
Returns:
  a `Spliterator` over the elements in this list
Since:
  1.8

### addFirst

default void addFirst(E e)
Adds an element as the first element of this collection (optional operation). After this operation completes normally, the given element will be a member of this collection, and it will be the first element in encounter order.

Specified by:
  `addFirst` in interface `SequencedCollection<E>`
Implementation Requirements:
  The implementation in this interface calls `add(0, e)`.
Parameters:
  `e` - the element to be added
Throws:
  `NullPointerException` - if the specified element is null and this collection does not permit null elements
  `UnsupportedOperationException` - if this collection implementation does not support this operation
Since:
  21

### addLast

default void addLast(E e)
Adds an element as the last element of this collection (optional operation). After this operation completes normally, the given element will be a member of this collection, and it will be the last element in encounter order.

Specified by:
  `addLast` in interface `SequencedCollection<E>`
Implementation Requirements:
  The implementation in this interface calls `add(e)`.
Parameters:
  `e` - the element to be added.
Throws:
  `NullPointerException` - if the specified element is null and this collection does not permit null elements
  `UnsupportedOperationException` - if this collection implementation does not support this operation
Since:
  21

### getFirst

default E getFirst()
Gets the first element of this collection.

Specified by:
  `getFirst` in interface `SequencedCollection<E>`
Implementation Requirements:
  If this List is not empty, the implementation in this interface returns the result of calling `get(0)`. Otherwise, it throws `NoSuchElementException`.
Returns:
  the retrieved element
Throws:
  `NoSuchElementException` - if this collection is empty
Since:
  21

### getLast

default E getLast()
Gets the last element of this collection.

Specified by:
  `getLast` in interface `SequencedCollection<E>`
Implementation Requirements:
  If this List is not empty, the implementation in this interface returns the result of calling `get(size() - 1)`. Otherwise, it throws `NoSuchElementException`.
Returns:
  the retrieved element
Throws:
  `NoSuchElementException` - if this collection is empty
Since:
  21

### removeFirst

default E removeFirst()
Removes and returns the first element of this collection (optional operation).

Specified by:
  `removeFirst` in interface `SequencedCollection<E>`
Implementation Requirements:
  If this List is not empty, the implementation in this interface returns the result of calling `remove(0)`. Otherwise, it throws `NoSuchElementException`.
Returns:
  the removed element
Throws:
  `NoSuchElementException` - if this collection is empty
  `UnsupportedOperationException` - if this collection implementation does not support this operation
Since:
  21

### removeLast

default E removeLast()
Removes and returns the last element of this collection (optional operation).

Specified by:
  `removeLast` in interface `SequencedCollection<E>`
Implementation Requirements:
  If this List is not empty, the implementation in this interface returns the result of calling `remove(size() - 1)`. Otherwise, it throws `NoSuchElementException`.
Returns:
  the removed element
Throws:
  `NoSuchElementException` - if this collection is empty
  `UnsupportedOperationException` - if this collection implementation does not support this operation
Since:
  21

### reversed

default List<E> reversed()
Returns a reverse-ordered view of this collection. The encounter order of elements in the returned view is the inverse of the encounter order of elements in this collection. The reverse ordering affects all order-sensitive operations, including those on the view collections of the returned view. If the collection implementation permits modifications to this view, the modifications "write through" to the underlying collection. Changes to the underlying collection might or might not be visible in this reversed view, depending upon the implementation.

Specified by:
  `reversed` in interface `SequencedCollection<E>`
Implementation Requirements:
  The implementation in this interface returns a reverse-ordered List view. The `reversed()` method of the view returns a reference to this List. Other operations on the view are implemented via calls to public methods on this List. The exact relationship between calls on the view and calls on this List is unspecified. However, order-sensitive operations generally delegate to the appropriate method with the opposite orientation. For example, calling `getFirst` on the view results in a call to `getLast` on this List.
Returns:
  a reverse-ordered view of this collection, as a `List`
Since:
  21

### of

static <E> List<E> of()
Returns an unmodifiable list containing zero elements. See Unmodifiable Lists for details.

Type Parameters:
  `E` - the `List`'s element type
Returns:
  an empty `List`
Since:
  9

### of

static <E> List<E> of(E e1)
Returns an unmodifiable list containing one element. See Unmodifiable Lists for details.

Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `e1` - the single element
Returns:
  a `List` containing the specified element
Throws:
  `NullPointerException` - if the element is `null`
Since:
  9

### of

static <E> List<E> of(E e1, E e2)
Returns an unmodifiable list containing two elements. See Unmodifiable Lists for details.

Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `e1` - the first element
  `e2` - the second element
Returns:
  a `List` containing the specified elements
Throws:
  `NullPointerException` - if an element is `null`
Since:
  9

### of

static <E> List<E> of(E e1, E e2, E e3)
Returns an unmodifiable list containing three elements. See Unmodifiable Lists for details.

Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `e1` - the first element
  `e2` - the second element
  `e3` - the third element
Returns:
  a `List` containing the specified elements
Throws:
  `NullPointerException` - if an element is `null`
Since:
  9

### of

static <E> List<E> of(E e1, E e2, E e3, E e4)
Returns an unmodifiable list containing four elements. See Unmodifiable Lists for details.

Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `e1` - the first element
  `e2` - the second element
  `e3` - the third element
  `e4` - the fourth element
Returns:
  a `List` containing the specified elements
Throws:
  `NullPointerException` - if an element is `null`
Since:
  9

### of

static <E> List<E> of(E e1, E e2, E e3, E e4, E e5)
Returns an unmodifiable list containing five elements. See Unmodifiable Lists for details.

Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `e1` - the first element
  `e2` - the second element
  `e3` - the third element
  `e4` - the fourth element
  `e5` - the fifth element
Returns:
  a `List` containing the specified elements
Throws:
  `NullPointerException` - if an element is `null`
Since:
  9

### of

static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6)
Returns an unmodifiable list containing six elements. See Unmodifiable Lists for details.

Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `e1` - the first element
  `e2` - the second element
  `e3` - the third element
  `e4` - the fourth element
  `e5` - the fifth element
  `e6` - the sixth element
Returns:
  a `List` containing the specified elements
Throws:
  `NullPointerException` - if an element is `null`
Since:
  9

### of

static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7)
Returns an unmodifiable list containing seven elements. See Unmodifiable Lists for details.

Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `e1` - the first element
  `e2` - the second element
  `e3` - the third element
  `e4` - the fourth element
  `e5` - the fifth element
  `e6` - the sixth element
  `e7` - the seventh element
Returns:
  a `List` containing the specified elements
Throws:
  `NullPointerException` - if an element is `null`
Since:
  9

### of

static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8)
Returns an unmodifiable list containing eight elements. See Unmodifiable Lists for details.

Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `e1` - the first element
  `e2` - the second element
  `e3` - the third element
  `e4` - the fourth element
  `e5` - the fifth element
  `e6` - the sixth element
  `e7` - the seventh element
  `e8` - the eighth element
Returns:
  a `List` containing the specified elements
Throws:
  `NullPointerException` - if an element is `null`
Since:
  9

### of

static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9)
Returns an unmodifiable list containing nine elements. See Unmodifiable Lists for details.

Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `e1` - the first element
  `e2` - the second element
  `e3` - the third element
  `e4` - the fourth element
  `e5` - the fifth element
  `e6` - the sixth element
  `e7` - the seventh element
  `e8` - the eighth element
  `e9` - the ninth element
Returns:
  a `List` containing the specified elements
Throws:
  `NullPointerException` - if an element is `null`
Since:
  9

### of

static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9, E e10)
Returns an unmodifiable list containing ten elements. See Unmodifiable Lists for details.

Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `e1` - the first element
  `e2` - the second element
  `e3` - the third element
  `e4` - the fourth element
  `e5` - the fifth element
  `e6` - the sixth element
  `e7` - the seventh element
  `e8` - the eighth element
  `e9` - the ninth element
  `e10` - the tenth element
Returns:
  a `List` containing the specified elements
Throws:
  `NullPointerException` - if an element is `null`
Since:
  9

### of

@SafeVarargs static <E> List<E> of(E... elements)
Returns an unmodifiable list containing an arbitrary number of elements. See Unmodifiable Lists for details.

API Note:
  This method also accepts a single array as an argument. The element type of the resulting list will be the component type of the array, and the size of the list will be equal to the length of the array. To create a list with a single element that is an array, do the following:

           String[] array = ... ;
           List<String[]> list = List.<String[]>of(array);

  This will cause the `List.of(E)` method to be invoked instead.
Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `elements` - the elements to be contained in the list
Returns:
  a `List` containing the specified elements
Throws:
  `NullPointerException` - if an element is `null` or if the array is `null`
Since:
  9

### copyOf

static <E> List<E> copyOf(Collection<? extends E> coll)
Returns an unmodifiable List containing the elements of the given Collection, in its iteration order. The given Collection must not be null, and it must not contain any null elements. If the given Collection is subsequently modified, the returned List will not reflect such modifications.

Implementation Note:
  If the given Collection is an unmodifiable List, calling copyOf will generally not create a copy.
Type Parameters:
  `E` - the `List`'s element type
Parameters:
  `coll` - a `Collection` from which elements are drawn, must be non-null
Returns:
  a `List` containing the elements of the given `Collection`
Throws:
  `NullPointerException` - if coll is null, or if it contains any nulls
Since:
  10