Inserts the specified element at the end of this deque.

  Inserts the specified element at the end of this deque.

This method is equivalent to ArrayDeque.addLast(E).
Returns: true (as specified by {@link Collection#add})
Parameters:
- e - the element to add
Throws:
- NullPointerException - if the specified element is null

  Inserts the specified element at the front of this deque.

  Inserts the specified element at the front of this deque.
Parameters:
- e - the element to add
Throws:
- NullPointerException - if the specified element is null

  Inserts the specified element at the end of this deque.

  Inserts the specified element at the end of this deque.

This method is equivalent to ArrayDeque.add(E).
Parameters:
- e - the element to add
Throws:
- NullPointerException - if the specified element is null

  Removes all of the elements from this deque.

  Removes all of the elements from this deque.
The deque will be empty after this call returns.

  Returns a copy of this deque.

  Returns a copy of this deque.
Returns: a copy of this deque

  Returns true if this deque contains the specified element.

  Returns true if this deque contains the specified element.
More formally, returns true if and only if this deque contains
at least one element e such that o.equals(e).
Returns: true if this deque contains the specified element
Parameters:
- o - object to be checked for containment in this deque

  Retrieves, but does not remove, the head of the queue represented by this deque.

  Retrieves, but does not remove, the head of the queue represented by this deque. This method differs from peek only in that it throws an exception if this deque is empty.

This method is equivalent to ArrayDeque.getFirst().
Returns: the head of the queue represented by this deque
Throws:
- NoSuchElementException - {@inheritDoc}

 

 
Throws:
- NoSuchElementException - {@inheritDoc}

 

 
Throws:
- NoSuchElementException - {@inheritDoc}

  Returns true if this deque contains no elements.

  Returns true if this deque contains no elements.
Returns: true if this deque contains no elements

  Returns an iterator over the elements in this deque.

  Returns an iterator over the elements in this deque. The elements
will be ordered from first (head) to last (tail). This is the same
order that elements would be dequeued (via successive calls to
ArrayDeque.remove() or popped (via successive calls to ArrayDeque.pop()).
Returns: an iterator over the elements in this deque

  Inserts the specified element at the end of this deque.

  Inserts the specified element at the end of this deque.

This method is equivalent to ArrayDeque.offerLast(E).
Returns: true (as specified by {@link Queue#offer})
Parameters:
- e - the element to add
Throws:
- NullPointerException - if the specified element is null

  Inserts the specified element at the front of this deque.

  Inserts the specified element at the front of this deque.
Returns: true (as specified by {@link Deque#offerFirst})
Parameters:
- e - the element to add
Throws:
- NullPointerException - if the specified element is null

  Inserts the specified element at the end of this deque.

  Inserts the specified element at the end of this deque.
Returns: true (as specified by {@link Deque#offerLast})
Parameters:
- e - the element to add
Throws:
- NullPointerException - if the specified element is null

  Retrieves, but does not remove, the head of the queue represented by this deque, or returns null if this deque is empty.

  Retrieves, but does not remove, the head of the queue represented by this deque, or returns null if this deque is empty.

This method is equivalent to ArrayDeque.peekFirst().
Returns: the head of the queue represented by this deque, or null if this deque is empty

  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.

  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.

This method is equivalent to ArrayDeque.pollFirst().
Returns: the head of the queue represented by this deque, or null if this deque is empty

  Pops an element from the stack represented by this deque.

  Pops an element from the stack represented by this deque. In other words, removes and returns the first element of this deque.

This method is equivalent to ArrayDeque.removeFirst().
Returns: the element at the front of this deque (which is the top of the stack represented by this deque)
Throws:
- NoSuchElementException - {@inheritDoc}

  Pushes an element onto the stack represented by this deque.

  Pushes an element onto the stack represented by this deque. In other words, inserts the element at the front of this deque.

This method is equivalent to ArrayDeque.addFirst(E).
Parameters:
- e - the element to push
Throws:
- NullPointerException - if the specified element is null

  Retrieves and removes the head of the queue represented by this deque.

  Retrieves and removes the head of the queue represented by this deque. This method differs from poll only in that it throws an exception if this deque is empty.

This method is equivalent to ArrayDeque.removeFirst().
Returns: the head of the queue represented by this deque
Throws:
- NoSuchElementException - {@inheritDoc}

  Removes a single instance of the specified element from this deque.

  Removes a single instance of the specified element from this deque. If the deque does not contain the element, it is unchanged. More formally, removes the first element e such that o.equals(e) (if such an element exists). Returns true if this deque contained the specified element (or equivalently, if this deque changed as a result of the call).

This method is equivalent to ArrayDeque.removeFirstOccurrence(java.lang.Object).
Returns: true if this deque contained the specified element
Parameters:
- o - element to be removed from this deque, if present

 

 
Throws:
- NoSuchElementException - {@inheritDoc}

  Removes the first occurrence of the specified element in this deque (when traversing the deque from head to tail).

  Removes the first occurrence of the specified element in this
deque (when traversing the deque from head to tail).
If the deque does not contain the element, it is unchanged.
More formally, removes the first element e such that
o.equals(e) (if such an element exists).
Returns true if this deque contained the specified element
(or equivalently, if this deque changed as a result of the call).
Returns: true if the deque contained the specified element
Parameters:
- o - element to be removed from this deque, if present

 

 
Throws:
- NoSuchElementException - {@inheritDoc}

  Removes the last occurrence of the specified element in this deque (when traversing the deque from head to tail).

  Removes the last occurrence of the specified element in this
deque (when traversing the deque from head to tail).
If the deque does not contain the element, it is unchanged.
More formally, removes the last element e such that
o.equals(e) (if such an element exists).
Returns true if this deque contained the specified element
(or equivalently, if this deque changed as a result of the call).
Returns: true if the deque contained the specified element
Parameters:
- o - element to be removed from this deque, if present

  Returns the number of elements in this deque.

  Returns the number of elements in this deque.
Returns: the number of elements in this deque

  Returns an array containing all of the elements in this deque in proper sequence (from first to last element).

  Returns an array containing all of the elements in this deque in proper sequence (from first to last element).

The returned array will be "safe" in that no references to it are maintained by this deque. (In other words, this method must allocate a new array). The caller is thus free to modify the returned array.

This method acts as bridge between array-based and collection-based APIs.
Returns: an array containing all of the elements in this deque

  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.

  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. If the deque 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 deque.

If this deque fits in the specified array with room to spare (i.e., the array has more elements than this deque), the element in the array immediately following the end of the deque is set to null.

Like the ArrayDeque.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 deque known to contain only strings. The following code can be used to dump the deque 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().
Returns: an array containing all of the elements in this deque
Parameters:
- a - 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
Throws:
- ArrayStoreException - if the runtime type of the specified array is not a supertype of the runtime type of every element in this deque
- NullPointerException - if the specified array is null