Added in API level 1

Summary: Fields | Protected Ctors | Methods | Protected Methods | Inherited Methods

AbstractList

public abstract class AbstractList
extends AbstractCollection<E> implements List<E>

java.lang.Object
↳	java.util.AbstractCollection<E>
	↳	java.util.AbstractList<E>

Known direct subclasses

AbstractSequentialList<E>, ArrayList<E>, Vector<E>

AbstractSequentialList<E>	This class provides a skeletal implementation of the `List` interface to minimize the effort required to implement this interface backed by a "sequential access" data store (such as a linked list).
ArrayList<E>	Resizable-array implementation of the `List` interface.
Vector<E>	The `Vector` class implements a growable array of objects.

Known indirect subclasses

LinkedList<E>, Stack<E>

LinkedList<E>	Doubly-linked list implementation of the `List` and `Deque` interfaces.
Stack<E>	The `Stack` class represents a last-in-first-out (LIFO) stack of objects.

This class provides a skeletal implementation of the List interface to minimize the effort required to implement this interface backed by a "random access" data store (such as an array). For sequential access data (such as a linked list), AbstractSequentialList should be used in preference to this class.

To implement an unmodifiable list, the programmer needs only to extend this class and provide implementations for the get(int) and size() methods.

To implement a modifiable list, the programmer must additionally override the set(int, E) method (which otherwise throws an UnsupportedOperationException). If the list is variable-size the programmer must additionally override the add(int, E) and remove(int) methods.

The programmer should generally provide a void (no argument) and collection constructor, as per the recommendation in the Collection interface specification.

Unlike the other abstract collection implementations, the programmer does not have to provide an iterator implementation; the iterator and list iterator are implemented by this class, on top of the "random access" methods: get(int), set(int, E), add(int, E) and remove(int).

The documentation for each non-abstract method in this class describes its implementation in detail. Each of these methods may be overridden if the collection being implemented admits a more efficient implementation.

This class is a member of the Java Collections Framework.

Summary

Fields
`protected int`	`modCount` The number of times this list has been structurally modified.

Protected constructors
`AbstractList()` Sole constructor.

Public methods
`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).
`void`	`clear()` Removes all of the elements from this list (optional operation).
`boolean`	`equals(Object o)` Compares the specified object with this list for equality.
`abstract E`	`get(int index)` Returns the element at the specified position in this list.
`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.
`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(int index)` Returns a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list.
`ListIterator<E>`	`listIterator()` Returns a list iterator over the elements in this list (in proper sequence).
`E`	`remove(int index)` Removes the element at the specified position in this list (optional operation).
`E`	`set(int index, E element)` Replaces the element at the specified position in this list with the specified element (optional operation).
`List<E>`	`subList(int fromIndex, int toIndex)` Returns a view of the portion of this list between the specified `fromIndex`, inclusive, and `toIndex`, exclusive.

Protected methods
`void`	`removeRange(int fromIndex, int toIndex)` Removes from this list all of the elements whose index is between `fromIndex`, inclusive, and `toIndex`, exclusive.

Inherited methods

From class


        
          java.util.AbstractCollection

`boolean`	`add(E e)` Ensures that this collection contains the specified element (optional operation).
`boolean`	`addAll(Collection<? extends E> c)` Adds all of the elements in the specified collection to this collection (optional operation).
`void`	`clear()` Removes all of the elements from this collection (optional operation).
`boolean`	`contains(Object o)` Returns `true` if this collection contains the specified element.
`boolean`	`containsAll(Collection<?> c)` Returns `true` if this collection contains all of the elements in the specified collection.
`boolean`	`isEmpty()` Returns `true` if this collection contains no elements.
`abstract Iterator<E>`	`iterator()` Returns an iterator over the elements contained in this collection.
`boolean`	`remove(Object o)` Removes a single instance of the specified element from this collection, if it is present (optional operation).
`boolean`	`removeAll(Collection<?> c)` Removes all of this collection's elements that are also contained in the specified collection (optional operation).
`boolean`	`retainAll(Collection<?> c)` Retains only the elements in this collection that are contained in the specified collection (optional operation).
`abstract int`	`size()` Returns the number of elements in this collection.
`<T> T[]`	`toArray(T[] a)` Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.
`Object[]`	`toArray()` Returns an array containing all of the elements in this collection.
`String`	`toString()` Returns a string representation of this collection.

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          java.util.Collection

`abstract boolean`	`add(E e)` Ensures that this collection contains the specified element (optional operation).
`abstract boolean`	`addAll(Collection<? extends E> c)` Adds all of the elements in the specified collection to this collection (optional operation).
`abstract void`	`clear()` Removes all of the elements from this collection (optional operation).
`abstract boolean`	`contains(Object o)` Returns `true` if this collection contains the specified element.
`abstract boolean`	`containsAll(Collection<?> c)` Returns `true` if this collection contains all of the elements in the specified collection.
`abstract boolean`	`equals(Object o)` Compares the specified object with this collection for equality.
`abstract int`	`hashCode()` Returns the hash code value for this collection.
`abstract boolean`	`isEmpty()` Returns `true` if this collection contains no elements.
`abstract Iterator<E>`	`iterator()` Returns an iterator over the elements in this collection.
`default Stream<E>`	`parallelStream()` Returns a possibly parallel `Stream` with this collection as its source.
`abstract boolean`	`remove(Object o)` Removes a single instance of the specified element from this collection, if it is present (optional operation).
`abstract boolean`	`removeAll(Collection<?> c)` Removes all of this collection's elements that are also contained in the specified collection (optional operation).
`default boolean`	`removeIf(Predicate<? super E> filter)` Removes all of the elements of this collection that satisfy the given predicate.
`abstract boolean`	`retainAll(Collection<?> c)` Retains only the elements in this collection that are contained in the specified collection (optional operation).
`abstract int`	`size()` Returns the number of elements in this collection.
`default Spliterator<E>`	`spliterator()` Creates a `Spliterator` over the elements in this collection.
`default Stream<E>`	`stream()` Returns a sequential `Stream` with this collection as its source.
`abstract <T> T[]`	`toArray(T[] a)` Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.
`abstract Object[]`	`toArray()` Returns an array containing all of the elements in this collection.
`default <T> T[]`	`toArray(IntFunction<T[]> generator)` Returns an array containing all of the elements in this collection, using the provided `generator` function to allocate the returned array.

From interface


        
          java.util.List

`abstract boolean`	`add(E e)` Appends the specified element to the end of this list (optional operation).
`abstract void`	`add(int index, E element)` Inserts the specified element at the specified position in this list (optional operation).
`abstract 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).
`abstract 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).
`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).
`abstract void`	`clear()` Removes all of the elements from this list (optional operation).
`abstract boolean`	`contains(Object o)` Returns `true` if this list contains the specified element.
`abstract 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.
`abstract boolean`	`equals(Object o)` Compares the specified object with this list for equality.
`abstract 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.
`abstract int`	`hashCode()` Returns the hash code value for this list.
`abstract 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.
`abstract boolean`	`isEmpty()` Returns `true` if this list contains no elements.
`abstract Iterator<E>`	`iterator()` Returns an iterator over the elements in this list in proper sequence.
`abstract 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.
`abstract 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.
`abstract ListIterator<E>`	`listIterator()` Returns a list iterator over the elements in this list (in proper sequence).
`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, 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)` 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, E e8)` Returns an unmodifiable list containing eight elements.
`static <E> List<E>`	`of(E... elements)` Returns an unmodifiable list containing an arbitrary number of elements.
`static <E> List<E>`	`of()` Returns an unmodifiable list containing zero 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.
`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, 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)` Returns an unmodifiable list containing four elements.
`static <E> List<E>`	`of(E e1)` Returns an unmodifiable list containing one element.
`abstract E`	`remove(int index)` Removes the element at the specified position in this list (optional operation).
`abstract boolean`	`remove(Object o)` Removes the first occurrence of the specified element from this list, if it is present (optional operation).
`abstract 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.
`abstract 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.
`abstract E`	`set(int index, E element)` Replaces the element at the specified position in this list with the specified element (optional operation).
`abstract 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.
`abstract List<E>`	`subList(int fromIndex, int toIndex)` Returns a view of the portion of this list between the specified `fromIndex`, inclusive, and `toIndex`, exclusive.
`abstract Object[]`	`toArray()` Returns an array containing all of the elements in this list in proper sequence (from first to last element).
`abstract <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.

From interface


        
          java.lang.Iterable

`default void`	`forEach(Consumer<? super T> action)` Performs the given action for each element of the `Iterable` until all elements have been processed or the action throws an exception.
`abstract Iterator<E>`	`iterator()` Returns an iterator over elements of type `T`.
`default Spliterator<E>`	`spliterator()` Creates a `Spliterator` over the elements described by this `Iterable`.

From interface


        
          java.util.SequencedCollection

`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).
`default E`	`getFirst()` Gets the first element of this collection.
`default E`	`getLast()` Gets the last element of this collection.
`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).
`abstract SequencedCollection<E>`	`reversed()` Returns a reverse-ordered view of this collection.

Fields

modCount

Added in API level 1

protected int modCount

The number of times this list has been structurally modified. Structural modifications are those that change the size of the list, or otherwise perturb it in such a fashion that iterations in progress may yield incorrect results.

This field is used by the iterator and list iterator implementation returned by the iterator and listIterator methods. If the value of this field changes unexpectedly, the iterator (or list iterator) will throw a ConcurrentModificationException in response to the next, remove, previous, set or add operations. This provides fail-fast behavior, rather than non-deterministic behavior in the face of concurrent modification during iteration.

Use of this field by subclasses is optional. If a subclass wishes to provide fail-fast iterators (and list iterators), then it merely has to increment this field in its add(int, E) and remove(int) methods (and any other methods that it overrides that result in structural modifications to the list). A single call to add(int, E) or remove(int) must add no more than one to this field, or the iterators (and list iterators) will throw bogus ConcurrentModificationExceptions. If an implementation does not wish to provide fail-fast iterators, this field may be ignored.

Protected constructors

AbstractList

Added in API level 1

protected AbstractList ()

Sole constructor. (For invocation by subclass constructors, typically implicit.)

Public methods

add

Added in API level 1

public 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).

Implementation Requirements:

This implementation always throws an UnsupportedOperationException.

Parameters
`index`	`int`: index at which the specified element is to be inserted
`element`	`E`: element to be inserted

Throws
`UnsupportedOperationException`
`ClassCastException`
`NullPointerException`
`IllegalArgumentException`
`IndexOutOfBoundsException`

add

Added in API level 1

public 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.

Implementation Requirements:

This implementation calls add(size(), e).
Note that this implementation throws an UnsupportedOperationException unless add(int, E) is overridden.

Parameters
`e`	`E`: element to be appended to this list

Returns
`boolean`	`true` (as specified by `Collection.add`)

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

addAll

Added in API level 1

public 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.)

Implementation Requirements:

This implementation gets an iterator over the specified collection and iterates over it, inserting the elements obtained from the iterator into this list at the appropriate position, one at a time, using add(int, E). Many implementations will override this method for efficiency.
Note that this implementation throws an UnsupportedOperationException unless add(int, E) is overridden.

Parameters
`index`	`int`: index at which to insert the first element from the specified collection
`c`	`Collection`: collection containing elements to be added to this list

Returns
`boolean`	`true` if this list changed as a result of the call

Throws
`UnsupportedOperationException`
`ClassCastException`
`NullPointerException`
`IllegalArgumentException`
`IndexOutOfBoundsException`

clear

Added in API level 1

public void clear ()

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

Implementation Requirements:

This implementation calls removeRange(0, size()).
Note that this implementation throws an UnsupportedOperationException unless remove(int index) or removeRange(int fromIndex, int toIndex) is overridden.

Throws
`UnsupportedOperationException`	if the `clear` operation is not supported by this list

equals

Added in API level 1

public 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 (e1==null ? e2==null : e1.equals(e2)).) In other words, two lists are defined to be equal if they contain the same elements in the same order.

Implementation Requirements:

This implementation first checks if the specified object is this list. If so, it returns true; if not, it checks if the specified object is a list. If not, it returns false; if so, it iterates over both lists, comparing corresponding pairs of elements. If any comparison returns false, this method returns false. If either iterator runs out of elements before the other it returns false (as the lists are of unequal length); otherwise it returns true when the iterations complete.

Parameters
`o`	`Object`: the object to be compared for equality with this list

Returns
`boolean`	`true` if the specified object is equal to this list

get

Added in API level 1

public abstract E get (int index)

Returns the element at the specified position in this list.

Parameters
`index`	`int`: index of the element to return

Returns
`E`	the element at the specified position in this list

Throws
`IndexOutOfBoundsException`

hashCode

Added in API level 1

public int hashCode ()

Returns the hash code value for this list.

Implementation Requirements:

This implementation uses exactly the code that is used to define the list hash function in the documentation for the List.hashCode method.

Returns
`int`	the hash code value for this list

indexOf

Added in API level 1

public 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.

Implementation Requirements:

This implementation first gets a list iterator (with listIterator()). Then, it iterates over the list until the specified element is found or the end of the list is reached.

Parameters
`o`	`Object`: element to search for

Returns
`int`	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`
`NullPointerException`

iterator

Added in API level 1

public Iterator<E> iterator ()

Returns an iterator over the elements in this list in proper sequence.

Implementation Requirements:

This implementation returns a straightforward implementation of the iterator interface, relying on the backing list's size(), get(int), and remove(int) methods.
Note that the iterator returned by this method will throw an UnsupportedOperationException in response to its remove method unless the list's remove(int) method is overridden.
This implementation can be made to throw runtime exceptions in the face of concurrent modification, as described in the specification for the (protected) modCount field.

Returns
`Iterator<E>`	an iterator over the elements in this list in proper sequence

lastIndexOf

Added in API level 1

public 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.

Implementation Requirements:

This implementation first gets a list iterator that points to the end of the list (with listIterator(size())). Then, it iterates backwards over the list until the specified element is found, or the beginning of the list is reached.

Parameters
`o`	`Object`: element to search for

Returns
`int`	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`
`NullPointerException`

listIterator

Added in API level 1

public 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.

Implementation Requirements:

This implementation returns a straightforward implementation of the ListIterator interface that extends the implementation of the Iterator interface returned by the iterator() method. The ListIterator implementation relies on the backing list's get(int), set(int, E), add(int, E) and remove(int) methods.
Note that the list iterator returned by this implementation will throw an UnsupportedOperationException in response to its remove, set and add methods unless the list's remove(int), set(int, E), and add(int, E) methods are overridden.
This implementation can be made to throw runtime exceptions in the face of concurrent modification, as described in the specification for the (protected) modCount field.

Parameters
`index`	`int`: index of the first element to be returned from the list iterator (by a call to `next`)

Returns
`ListIterator<E>`	a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list

Throws
`IndexOutOfBoundsException`

listIterator

Added in API level 1

public ListIterator<E> listIterator ()

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

Implementation Requirements:

This implementation returns listIterator(0).

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

See also:

listIterator(int)

remove

Added in API level 1

public 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.

Implementation Requirements:

This implementation always throws an UnsupportedOperationException.

Parameters
`index`	`int`: the index of the element to be removed

Returns
`E`	the element previously at the specified position

Throws
`UnsupportedOperationException`
`IndexOutOfBoundsException`

set

Added in API level 1

public E set (int index, 
                E element)

Replaces the element at the specified position in this list with the specified element (optional operation).

Implementation Requirements:

This implementation always throws an UnsupportedOperationException.

Parameters
`index`	`int`: index of the element to replace
`element`	`E`: element to be stored at the specified position

Returns
`E`	the element previously at the specified position

Throws
`UnsupportedOperationException`
`ClassCastException`
`NullPointerException`
`IllegalArgumentException`
`IndexOutOfBoundsException`

subList

Added in API level 1

public 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.)

Implementation Requirements:

This implementation returns a list that subclasses AbstractList. The subclass stores, in private fields, the size of the subList (which can change over its lifetime), and the expected modCount value of the backing list. There are two variants of the subclass, one of which implements RandomAccess. If this list implements RandomAccess the returned list will be an instance of the subclass that implements RandomAccess.
The subclass's set(int, E), get(int), add(int, E), remove(int), addAll(int, Collection) and removeRange(int, int) methods all delegate to the corresponding methods on the backing abstract list, after bounds-checking the index and adjusting for the offset. The addAll(Collection c) method merely returns addAll(size, c).
The listIterator(int) method returns a "wrapper object" over a list iterator on the backing list, which is created with the corresponding method on the backing list. The iterator method merely returns listIterator(), and the size method merely returns the subclass's size field.
All methods first check to see if the actual modCount of the backing list is equal to its expected value, and throw a ConcurrentModificationException if it is not.

Parameters
`fromIndex`	`int`: low endpoint (inclusive) of the subList
`toIndex`	`int`: high endpoint (exclusive) of the subList

Returns
`List<E>`	a view of the specified range within this list

Throws
`IndexOutOfBoundsException`	if an endpoint index value is out of range `(fromIndex < 0 \|\| toIndex > size)`
`IllegalArgumentException`	if the endpoint indices are out of order `(fromIndex > toIndex)`

Protected methods

removeRange

Added in API level 1

protected void removeRange (int fromIndex, 
                int toIndex)

Removes from this list all of the elements whose index is between fromIndex, inclusive, and toIndex, exclusive. Shifts any succeeding elements to the left (reduces their index). This call shortens the list by (toIndex - fromIndex) elements. (If toIndex==fromIndex, this operation has no effect.)

This method is called by the clear operation on this list and its subLists. Overriding this method to take advantage of the internals of the list implementation can substantially improve the performance of the clear operation on this list and its subLists.

Implementation Requirements:

This implementation gets a list iterator positioned before fromIndex, and repeatedly calls ListIterator.next followed by ListIterator.remove until the entire range has been removed. Note: if ListIterator.remove requires linear time, this implementation requires quadratic time.

Parameters
`fromIndex`	`int`: index of first element to be removed
`toIndex`	`int`: index after last element to be removed