Resizable-array implementation of the Deque interface. Null elements are prohibited. This class is likely to be faster than Stack when used as a stack, and faster than LinkedList when used as a queue.
| Constructor | Description |
|---|---|
ArrayDeque() |
Constructs an empty array deque with an initial capacity sufficient to hold 16 elements. |
ArrayDeque(Collection<? extends E> c) |
Constructs a deque containing the elements of the specified collection, in the order they are returned by the collection's iterator. |
StringBuilder(int initCapacity) |
Creates an empty string builder with the specified initial capacity. |
ArrayDeque(int numElements) |
Constructs an empty array deque with an initial capacity sufficient to hold the specified number of elements. |
| Method | Description |
|---|---|
| public boolean offerFirst(E e) | Inserts the specified element at the front of this deque. |
| public boolean offerLast(E e) | Inserts the specified element at the end of this deque. |
| public E pollFirst() | Retrieves and removes the first element of this deque, or returns null if this deque is empty. |
| public E pollLast() | Retrieves and removes the last element of this deque, or returns null if this deque is empty. |
| public E peekFirst() | Retrieves, but does not remove, the first element of this deque, or returns null if this deque is empty. |
| public E peekLast() | Retrieves, but does not remove, the last element of this deque, or returns null if this deque is empty. |
| public int size() | Returns the number of elements in this deque. |
| public boolean isEmpty() | Returns true if this deque contains no elements. |
| public void clear() | Removes all of the elements from this deque. The deque will be empty after this call returns. |