How does ArrayDeque impact performance or memory usage?

ArrayDeque is a resizable-array implementation of the Deque interface in Java that is designed to provide efficient storage and retrieval of data. Its performance and memory usage characteristics make it a suitable choice for various applications.

Performance Impact

ArrayDeque offers constant time (O(1)) performance for adding and removing elements from both ends of the queue. This makes it highly efficient for operations such as enqueue and dequeue. Unlike LinkedList, which also implements Deque, ArrayDeque has a lower memory overhead due to its array-based structure, leading to better cache performance as well.

Memory Usage

ArrayDeque dynamically resizes itself as more elements are added, which means it can use more memory than a fixed-size data structure. However, this can lead to considerable efficiency when dealing with a growing number of elements, as it minimizes the need for multiple reallocations. The downsize is that there may be empty slots in the underlying array, leading to a slight increase in memory usage compared to a tightly packed data structure.

Example Usage

// Importing ArrayDeque class import java.util.ArrayDeque; public class Example { public static void main(String[] args) { // Creating an ArrayDeque instance ArrayDeque deque = new ArrayDeque<>(); // Adding elements deque.add("Apple"); deque.add("Banana"); deque.addFirst("Cherry"); // Removing elements String firstElement = deque.removeFirst(); // Cherry String lastElement = deque.removeLast(); // Banana // Display the remaining element System.out.println("Remaining Element: " + deque.peek()); // Apple } }

ArrayDeque performance memory usage Java data structure