The ArrayDeque Class
Java SE 6 added the ArrayDeque class, which extends AbstractCollection and implements
the Deque interface. It adds no methods of its own. ArrayDeque creates a dynamic array
and has no capacity restrictions. (The Deque interface supports implementations that
restrict capacity, but does not require such restrictions.) ArrayDeque is a generic class that
has this declaration:
class ArrayDeque<E>
Here, E specifies the type of objects stored in the collection.
ArrayDeque defines the following constructors:
ArrayDeque( )
ArrayDeque(int size)
ArrayDeque(Collection<? extends E> c)
The first constructor builds an empty deque. Its starting capacity is 16. The second
constructor builds a deque that has the specified initial capacity. The third constructor
creates a deque that is initialized with the elements of the collection passed in c. In all cases,
the capacity grows as needed to handle the elements added to the deque.
The following program demonstrates ArrayDeque by using it to create a stack:
// Demonstrate ArrayDeque.
import java.util.*;
class ArrayDequeDemo {
public static void main(String args[]) {
// Create a tree set.
ArrayDeque<String> adq = new ArrayDeque<String>();
// Use an ArrayDeque like a stack.
adq.push("A");
adq.push("B");
adq.push("D");
adq.push("E");
adq.push("F");
System.out.print("Popping the stack: ");
while(adq.peek() != null)
System.out.print(adq.pop() + " ");
System.out.println();
}
}
The output is shown here:
Popping the stack: F E D B A
Search WWH :
