Vector and ArrayDeque classes
arrays, class, java, vector
Solution
The basics are:
`Vector` implements `java.util.List`, which defines containers that allow index-based access to elements. It also implements `interface RandomAccess`, which indicates to the user that the underlying representation allows fast (typically `O(1)`) access to elements.
`ArrayDeque` implements `java.util.Deque`, which defines a container that supports fast element adding and removal from the beginning and end of the container.
Major differences:
`Vector` supports adding elements into the middle of the container, using the overloaded versions of `List.add(int index, E element)` or `List.addAll(int index, Collection<? extends E> c)`.
`Vector` supports removing elements from the middle of the container, using the `remove` method.
`Vector`'s `set` and `setElementAt` methods allow you to do an in-place element swap (replace one object in the `Vector` with another one, an `O(1)` operation).
`add`ing to the end of a `Vector` is amortized constant time. Adding to the beginning or middle of the vector is a linear time operation (`O(n)`).
`ArrayDeque` has amortized constant time (`O(1)`) adding/deletion of elements at both the front and back of the container.
`ArrayDeque` does not allow you to specifically remove an element at a certain position in the container. The various `remove`, `removeFirst`, and `removeLast` methods of the class allow you a slightly more limited element removal.
`ArrayDeque` comes with methods for using the class like a queue (`peek`, `poll`, `add`, `addFirst`) and like a stack (`offer`, `push`, `pop`, `peekLast`, `addLast`), or like both (hence why it is a Double-Ended Queue).
`ArrayDeque` has no support for adding elements into the middle of the deque.
`Vector` has special `ListIterator`s which allows you to get an iterator that starts at a specific location in the container, and also support adding, removing, and setting elements. `ArrayDeque`'s iterators do not support those extra methods.
`Vector` is a synchronized container, meaning that it already contains code to perform synchronization/locking for multithreaded environments. For `ArrayDeque`, you have to provide your own synchronization code if you're doing multithreaded access to the container. Note that `ArrayList` is an unsynchronized counterpart to `Vector`.
Problem
What is the diffirence between Vector and ArrayDeque classes? I read about the ArrayDeque class yesterday, while I have used Vector class before.