OpenJDK 1.22 · java.util.ArrayDeque · APIdia, the JavaDoc alternative

Modifier and Type	Class and Description
private class	ArrayDeque.DeqIterator
pack-priv class	ArrayDeque.DeqSpliterator
private class	ArrayDeque.DescendingIterator

Modifier and Type	Field and Description
pack-priv transient Object[]	elements The array in which the elements of the deque are stored.
pack-priv transient int	head The index of the element at the head of the deque (which is the element that would be removed by remove() or pop()); or an arbitrary number 0 <= head < elements.length equal to tail if the deque is empty.
private static final int	MAX_ARRAY_SIZE The maximum size of array to allocate.
private static final long	serialVersionUID
pack-priv transient int	tail The index at which the next element would be added to the tail of the deque (via addLast(E), add(E), or push(E)); elements[tail] is always null.

Access	Constructor and Description
public	ArrayDeque() Constructs an empty array deque with an initial capacity sufficient to hold 16 elements.
public	ArrayDeque(int lower bound on initial capacity of the deque numElements) Constructs an empty array deque with an initial capacity sufficient to hold the specified number of elements.
public	ArrayDeque(Collection<? extends E> the collection whose elements are to be placed into the deque c) Constructs a deque containing the elements of the specified collection, in the order they are returned by the collection's iterator.

Method Summary

Modifier and Type	Method and Description
public boolean	Returns: `true` (as specified by `Collection#add`) add(E the element to add e) Overrides java.util.AbstractCollection.add. Implements java.util.Deque.add, java.util.Collection.add. Inserts the specified element at the end of this deque.
public boolean	Returns: `true` if this deque changed as a result of the call addAll(Collection<? extends E> the elements to be inserted into this deque c) Overrides java.util.AbstractCollection.addAll. Implements java.util.Deque.addAll, java.util.Collection.addAll. Adds all of the elements in the specified collection at the end of this deque, as if by calling `addLast` on each one, in the order that they are returned by the collection's iterator.
public void	addFirst(E the element to add e) Implements java.util.Deque.addFirst. Inserts the specified element at the front of this deque.
public void	addLast(E the element to add e) Implements java.util.Deque.addLast. Inserts the specified element at the end of this deque.
private boolean	bulkRemove(Predicate<? super E> filter) Implementation of bulk remove methods.
private boolean	bulkRemoveModified(Predicate<? super E> filter, final int valid index of first element to be deleted beg) Helper for bulkRemove, in case of at least one deletion.
pack-priv void	checkInvariants() debugging
private static void	circularClear(Object[] es, int i, int end) Nulls out slots starting at array index i, up to index end.
public void	clear() Overrides java.util.AbstractCollection.clear. Implements java.util.Collection.clear. Removes all of the elements from this deque.
public ArrayDeque<E>	Returns: a copy of this deque clone() Overrides java.lang.Object.clone. Returns a copy of this deque.
public boolean	Returns: `true` if this deque contains the specified element contains(Object object to be checked for containment in this deque o) Overrides java.util.AbstractCollection.contains. Implements java.util.Deque.contains, java.util.Collection.contains. Returns `true` if this deque contains the specified element.
private void	copyElements(Collection<? extends E> c)
pack-priv static final int	dec(int i, int modulus) Circularly decrements i, mod modulus.
pack-priv boolean	Returns: true if elements near tail moved backwards delete(int i) Removes the element at the specified position in the elements array.
public Iterator<E>	descendingIterator() Implements java.util.Deque.descendingIterator. Returns an iterator over the elements in this deque in reverse sequential order.
public E	Returns: the head of the queue represented by this deque element() Implements java.util.Deque.element. Retrieves, but does not remove, the head of the queue represented by this deque.
pack-priv static final <E> E	elementAt(Object[] es, int i) Returns element at array index i.
public void	forEach(Consumer<? super E> The action to be performed for each element action) Overrides default java.lang.Iterable.forEach. Performs the given action for each element of the `Iterable` until all elements have been processed or the action throws an exception.
public E	getFirst() Implements java.util.Deque.getFirst. Retrieves, but does not remove, the first element of this deque.
public E	getLast() Implements java.util.Deque.getLast. Retrieves, but does not remove, the last element of this deque.
private void	grow(int the required minimum extra capacity; must be positive needed) Increases the capacity of this deque by at least the given amount.
pack-priv static final int	inc(int i, int modulus) Circularly increments i, mod modulus.
pack-priv static final int	Returns: index 0 <= i < modulus inc(int i, int distance, int modulus) Circularly adds the given distance to index i, mod modulus.
private static boolean	isClear(long[] bits, int i)
public boolean	Returns: `true` if this deque contains no elements isEmpty() Overrides java.util.AbstractCollection.isEmpty. Implements java.util.Collection.isEmpty. Returns `true` if this deque contains no elements.
public Iterator<E>	Returns: an iterator over the elements in this deque iterator() Implements abstract java.util.AbstractCollection.iterator. Implements java.util.Deque.iterator, java.util.Collection.iterator. Returns an iterator over the elements in this deque.
private static long[]	nBits(int n)
private int	newCapacity(int needed, int jump) Capacity calculation for edge conditions, especially overflow.
pack-priv static final <E> E	nonNullElementAt(Object[] es, int i) A version of elementAt that checks for null elements.
public boolean	Returns: `true` (as specified by `Queue#offer`) offer(E the element to add e) Implements java.util.Deque.offer. Inserts the specified element at the end of this deque.
public boolean	Returns: `true` (as specified by `Deque#offerFirst`) offerFirst(E the element to add e) Implements java.util.Deque.offerFirst. Inserts the specified element at the front of this deque.
public boolean	Returns: `true` (as specified by `Deque#offerLast`) offerLast(E the element to add e) Implements java.util.Deque.offerLast. Inserts the specified element at the end of this deque.
public E	Returns: the head of the queue represented by this deque, or `null` if this deque is empty peek() Implements java.util.Deque.peek. Retrieves, but does not remove, the head of the queue represented by this deque, or returns `null` if this deque is empty.
public E	peekFirst() Implements java.util.Deque.peekFirst. Retrieves, but does not remove, the first element of this deque, or returns `null` if this deque is empty.
public E	peekLast() Implements java.util.Deque.peekLast. Retrieves, but does not remove, the last element of this deque, or returns `null` if this deque is empty.
public E	Returns: the head of the queue represented by this deque, or `null` if this deque is empty poll() Implements java.util.Deque.poll. Retrieves and removes the head of the queue represented by this deque (in other words, the first element of this deque), or returns `null` if this deque is empty.
public E	pollFirst() Implements java.util.Deque.pollFirst. Retrieves and removes the first element of this deque, or returns `null` if this deque is empty.
public E	pollLast() Implements java.util.Deque.pollLast. Retrieves and removes the last element of this deque, or returns `null` if this deque is empty.
public E	Returns: the element at the front of this deque (which is the top of the stack represented by this deque) pop() Implements java.util.Deque.pop. Pops an element from the stack represented by this deque.
public void	push(E the element to push e) Implements java.util.Deque.push. Pushes an element onto the stack represented by this deque.
private void	readObject(ObjectInputStream the stream s) Reconstitutes this deque from a stream (that is, deserializes it).
public E	Returns: the head of the queue represented by this deque remove() Implements java.util.Deque.remove. Retrieves and removes the head of the queue represented by this deque.
public boolean	Returns: `true` if this deque contained the specified element remove(Object element to be removed from this deque, if present o) Overrides java.util.AbstractCollection.remove. Implements java.util.Deque.remove, java.util.Collection.remove. Removes a single instance of the specified element from this deque.
public boolean	removeAll(Collection<?> collection containing elements to be removed from this collection c) Overrides java.util.AbstractCollection.removeAll. Implements java.util.Collection.removeAll. Removes all of this collection's elements that are also contained in the specified collection (optional operation).
public E	removeFirst() Implements java.util.Deque.removeFirst. Retrieves and removes the first element of this deque.
public boolean	Returns: `true` if the deque contained the specified element removeFirstOccurrence(Object element to be removed from this deque, if present o) Implements java.util.Deque.removeFirstOccurrence. Removes the first occurrence of the specified element in this deque (when traversing the deque from head to tail).
public boolean	removeIf(Predicate<? super E> a predicate which returns `true` for elements to be removed filter) Overrides default java.util.Collection.removeIf. Removes all of the elements of this collection that satisfy the given predicate (optional operation).
public E	removeLast() Implements java.util.Deque.removeLast. Retrieves and removes the last element of this deque.
public boolean	Returns: `true` if the deque contained the specified element removeLastOccurrence(Object element to be removed from this deque, if present o) Implements java.util.Deque.removeLastOccurrence. Removes the last occurrence of the specified element in this deque (when traversing the deque from head to tail).
public boolean	retainAll(Collection<?> collection containing elements to be retained in this collection c) Overrides java.util.AbstractCollection.retainAll. Implements java.util.Collection.retainAll. Retains only the elements in this collection that are contained in the specified collection (optional operation).
private static void	setBit(long[] bits, int i)
public int	Returns: the number of elements in this deque size() Implements abstract java.util.AbstractCollection.size. Implements java.util.Deque.size, java.util.Collection.size. Returns the number of elements in this deque.
public Spliterator<E>	Returns: a `Spliterator` over the elements in this deque spliterator() Overrides default java.util.Collection.spliterator. Creates a late-binding and fail-fast `Spliterator` over the elements in this deque.
pack-priv static final int	Returns: the "circular distance" from j to i; corner case i == j is disambiguated to "empty", returning 0. sub(int i, int j, int modulus) Subtracts j from i, mod modulus.
public Object[]	Returns: an array containing all of the elements in this deque toArray() Overrides java.util.AbstractCollection.toArray. Implements java.util.Collection.toArray. Returns an array containing all of the elements in this deque in proper sequence (from first to last element).
private <T> T[]	toArray(Class<T[]> klazz)
public <T> T[]	Returns: an array containing all of the elements in this deque toArray(T[] the array into which the elements of the deque are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose a) Overrides java.util.AbstractCollection.toArray. Implements java.util.Collection.toArray. Returns an array containing all of the elements in this deque in proper sequence (from first to last element); the runtime type of the returned array is that of the specified array.
private void	writeObject(ObjectOutputStream the stream s) Saves this deque to a stream (that is, serializes it).

Inherited from java.util.AbstractCollection:: containsAll toString

public Class ArrayDeque<E>

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary