ArrayList Class
Definition
Important
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Resizable-array implementation of the List interface.
[Android.Runtime.Register("java/util/ArrayList", DoNotGenerateAcw=true)]
[Java.Interop.JavaTypeParameters(new System.String[] { "E" })]
public class ArrayList : Java.Util.AbstractList, IDisposable, Java.IO.ISerializable, Java.Lang.ICloneable, Java.Util.IRandomAccess[<Android.Runtime.Register("java/util/ArrayList", DoNotGenerateAcw=true)>]
[<Java.Interop.JavaTypeParameters(new System.String[] { "E" })>]
type ArrayList = class
inherit AbstractList
interface ISerializable
interface IJavaObject
interface IDisposable
interface IJavaPeerable
interface ICloneable
interface IList
interface ICollection
interface IIterable
interface ISequencedCollection
interface IRandomAccess- Inheritance
- Attributes
- Implements
Remarks
Resizable-array implementation of the List interface. Implements all optional list operations, and permits all elements, including null. In addition to implementing the List interface, this class provides methods to manipulate the size of the array that is used internally to store the list. (This class is roughly equivalent to Vector, except that it is unsynchronized.)
The size, isEmpty, get, set, iterator, and listIterator operations run in constant time. The add operation runs in amortized constant time, that is, adding n elements requires O(n) time. All of the other operations run in linear time (roughly speaking). The constant factor is low compared to that for the LinkedList implementation.
Each ArrayList instance has a capacity. The capacity is the size of the array used to store the elements in the list. It is always at least as large as the list size. As elements are added to an ArrayList, its capacity grows automatically. The details of the growth policy are not specified beyond the fact that adding an element has constant amortized time cost.
An application can increase the capacity of an ArrayList instance before adding a large number of elements using the ensureCapacity operation. This may reduce the amount of incremental reallocation.
<strong>Note that this implementation is not synchronized.</strong> If multiple threads access an ArrayList instance concurrently, and at least one of the threads modifies the list structurally, it must be synchronized externally. (A structural modification is any operation that adds or deletes one or more elements, or explicitly resizes the backing array; merely setting the value of an element is not a structural modification.) This is typically accomplished by synchronizing on some object that naturally encapsulates the list.
If no such object exists, the list should be "wrapped" using the Collections#synchronizedList Collections.synchronizedList method. This is best done at creation time, to prevent accidental unsynchronized access to the list:
List list = Collections.synchronizedList(new ArrayList(...));
The iterators returned by this class's #iterator() iterator and #listIterator(int) listIterator methods are <em>fail-fast</em>: if the list is structurally modified at any time after the iterator is created, in any way except through the iterator's own ListIterator#remove() remove or ListIterator#add(Object) add methods, the 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.
Note that the fail-fast behavior of an iterator cannot be guaranteed as it is, generally speaking, impossible to make any hard guarantees in the presence of unsynchronized concurrent modification. Fail-fast iterators throw ConcurrentModificationException on a best-effort basis. Therefore, it would be wrong to write a program that depended on this exception for its correctness: the fail-fast behavior of iterators should be used only to detect bugs.
This class is a member of the Java Collections Framework.
Added in 1.2.
Java documentation for java.util.ArrayList.
Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.
Constructors
| Name | Description |
|---|---|
| ArrayList() |
Constructs an empty list with an initial capacity of ten. |
| ArrayList(ICollection) |
Constructs a list containing the elements of the specified collection, in the order they are returned by the collection's iterator. |
| ArrayList(Int32) |
Constructs an empty list with the specified initial capacity. |
| ArrayList(IntPtr, JniHandleOwnership) |
A constructor used when creating managed representations of JNI objects; called by the runtime. |
Properties
| Name | Description |
|---|---|
| Class |
Returns the runtime class of this |
| First |
Gets the first element of this collection. |
| Handle |
The handle to the underlying Android instance. (Inherited from Object) |
| IsEmpty |
Returns true if this collection contains no elements. (Inherited from AbstractCollection) |
| JniIdentityHashCode |
Gets the identity hash code assigned to this Java peer by the interop runtime. (Inherited from Object) |
| JniManagedPeerState | (Inherited from JavaObject) |
| JniPeerMembers |
Gets the JNI metadata used to access members of this Java binding. |
| Last |
Gets the last element of this collection. |
| ModCount |
The number of times this list has been structurally modified. (Inherited from AbstractList) |
| PeerReference |
Gets the JNI object reference for this Java peer. (Inherited from Object) |
| ThresholdClass |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
| ThresholdType |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
Methods
| Name | Description |
|---|---|
| Add(Int32, Object) |
Inserts the specified element at the specified position in this list (optional operation). (Inherited from AbstractList) |
| Add(Object) |
Ensures that this collection contains the specified element (optional operation). (Inherited from AbstractCollection) |
| AddAll(ICollection) |
Adds all of the elements in the specified collection to this collection (optional operation). (Inherited from AbstractCollection) |
| AddAll(Int32, ICollection) |
Inserts all of the elements in the specified collection into this list at the specified position (optional operation). (Inherited from AbstractList) |
| AddFirst(Object) |
Adds an element as the first element of this collection (optional operation). |
| AddLast(Object) |
Adds an element as the last element of this collection (optional operation). |
| Clear() |
Removes all of the elements from this collection (optional operation). (Inherited from AbstractCollection) |
| Clone() |
Returns a shallow copy of this |
| Construct(JniObjectReference, JniObjectReferenceOptions) | (Inherited from JavaObject) |
| Contains(Object) |
Returns true if this collection contains the specified element. (Inherited from AbstractCollection) |
| ContainsAll(ICollection) |
Returns true if this collection contains all of the elements in the specified collection. (Inherited from AbstractCollection) |
| Dispose() |
Releases the resources held by this Java peer. (Inherited from Object) |
| Dispose(Boolean) |
Releases the resources held by this Java peer. (Inherited from Object) |
| DisposeUnlessReferenced() | (Inherited from JavaObject) |
| EnsureCapacity(Int32) |
Increases the capacity of this |
| Equals(Object) | (Inherited from JavaObject) |
| Equals(Object) |
Indicates whether some other object is "equal to" this one. (Inherited from Object) |
| ForEach(IConsumer) |
Performs the given action for each element of the Iterable until all elements have been processed or the action throws an exception. |
| Get(Int32) |
Returns the element at the specified position in this list. |
| GetHashCode() |
Returns a hash code value for the object. (Inherited from Object) |
| IndexOf(Object) |
Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element. (Inherited from AbstractList) |
| Iterator() |
Returns an iterator over the elements in this list in proper sequence. (Inherited from AbstractList) |
| JavaFinalize() |
Obsolete.
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. (Inherited from Object) |
| LastIndexOf(Object) |
Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element. (Inherited from AbstractList) |
| ListIterator() |
Returns a list iterator over the elements in this list (in proper sequence). (Inherited from AbstractList) |
| ListIterator(Int32) |
Returns a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list. (Inherited from AbstractList) |
| Notify() |
Wakes up a single thread that is waiting on this object's monitor. (Inherited from Object) |
| NotifyAll() |
Wakes up all threads that are waiting on this object's monitor. (Inherited from Object) |
| Remove(Int32) |
Removes the element at the specified position in this list (optional operation). (Inherited from AbstractList) |
| Remove(Object) |
Removes a single instance of the specified element from this collection, if it is present (optional operation). (Inherited from AbstractCollection) |
| RemoveAll(ICollection) |
Removes all of this collection's elements that are also contained in the specified collection (optional operation). (Inherited from AbstractCollection) |
| RemoveFirst() |
Removes and returns the first element of this collection (optional operation). |
| RemoveIf(IPredicate) |
Removes all of the elements of this collection that satisfy the given predicate. |
| RemoveLast() |
Removes and returns the last element of this collection (optional operation). |
| RemoveRange(Int32, Int32) |
Removes from this list all of the elements whose index is between
|
| ReplaceAll(IUnaryOperator) | |
| RetainAll(ICollection) |
Retains only the elements in this collection that are contained in the specified collection (optional operation). (Inherited from AbstractCollection) |
| Set(Int32, Object) |
Replaces the element at the specified position in this list with the specified element (optional operation). (Inherited from AbstractList) |
| SetHandle(IntPtr, JniHandleOwnership) |
Sets the Handle property. (Inherited from Object) |
| SetPeerReference(JniObjectReference, JniObjectReferenceOptions) | (Inherited from JavaObject) |
| Size() |
Returns the number of elements in this list. |
| Sort(IComparator) | |
| Spliterator() |
Creates a <em>late-binding</em>
and <em>fail-fast</em> |
| SubList(Int32, Int32) |
Returns a view of the portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive. (Inherited from AbstractList) |
| ToArray() |
Returns an array containing all of the elements in this collection. (Inherited from AbstractCollection) |
| ToArray(Object[]) |
Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array. (Inherited from AbstractCollection) |
| ToArray<T>() |
Creates a managed array from this Java array wrapper. (Inherited from Object) |
| ToString() |
Returns a string representation of the object. (Inherited from Object) |
| TrimToSize() |
Trims the capacity of this |
| UnregisterFromRuntime() |
Unregisters this Java peer from the interop runtime. (Inherited from Object) |
| Wait() |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>. (Inherited from Object) |
| Wait(Int64, Int32) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
| Wait(Int64) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
Explicit Interface Implementations
| Name | Description |
|---|---|
| IJavaPeerable.Disposed() | (Inherited from JavaObject) |
| IJavaPeerable.Finalized() | (Inherited from JavaObject) |
| IJavaPeerable.JniObjectReferenceControlBlock | (Inherited from JavaObject) |
| IJavaPeerable.SetJniIdentityHashCode(Int32) | (Inherited from JavaObject) |
| IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates) | (Inherited from JavaObject) |
| IJavaPeerable.SetPeerReference(JniObjectReference) | (Inherited from JavaObject) |
| IJavaPeerable.UnregisterFromRuntime() |
Removes this instance from the runtime's Java object lookup. |
Extension Methods
| Name | Description |
|---|---|
| GetJniTypeName(IJavaPeerable) |
Gets the JNI name of the type of the instance |
| JavaAs<TResult>(IJavaPeerable) |
Try to coerce |
| JavaCast<TResult>(IJavaObject) |
Performs an Android runtime-checked type conversion. |
| JavaCast<TResult>(IJavaObject) | |
| ToEnumerable(IIterable) |
Returns an IEnumerable that iterates over a Java
IIterable, allowing |
| ToEnumerable<T>(IIterable) |
Returns an IEnumerable<T> that iterates over a Java
IIterable, marshaling each element to |
| TryJavaCast<TResult>(IJavaPeerable, TResult) |
Try to coerce |