Java中的ArrayDeque descendingIterator() 方法

Java.util.ArrayDeque.descendingIterator() 方法用于返回与 ArrayDeque 相同但顺序相反的元素的迭代器。

句法：

Iterator iterate_value = Array_Deque.descendingIterator();

参数：该方法不带任何参数。

返回值：该方法迭代双端队列的元素并以相反的顺序返回值（迭代器）。

下面的程序说明了Java.util.ArrayDeque.descendingIterator() 方法：
方案一：

// Java code to illustrate descendingIterator()
import java.util.*;
  
public class ArrayDequeDemo {
    public static void main(String args[])
    {
        // Creating an empty ArrayDeque
        Deque de_que = new ArrayDeque();
  
        // Use add() method to add elements into the Queue
        de_que.add("Welcome");
        de_que.add("To");
        de_que.add("Geeks");
        de_que.add("4");
        de_que.add("Geeks");
  
        // Displaying the ArrayDeque
        System.out.println("ArrayDeque: " + de_que);
  
        // Creating a desc_iterator
        Iterator value = de_que.descendingIterator();
  
        // Displaying the values after iterating through the Deque
        // in reverse order
        System.out.println("The iterator values are: ");
        while (value.hasNext()) {
            System.out.println(value.next());
        }
    }
}

输出：

ArrayDeque: [Welcome, To, Geeks, 4, Geeks]
The iterator values are: 
Geeks
4
Geeks
To
Welcome

方案二：

// Java code to illustrate descendingIterator()
import java.util.*;
  
public class ArrayDequeDemo {
    public static void main(String args[])
    {
        // Creating an empty ArrayDeque
        Deque de_que = new ArrayDeque();
  
        // Use add() method to add elements into the Queue
        de_que.add(10);
        de_que.add(15);
        de_que.add(30);
        de_que.add(20);
        de_que.add(5);
  
        // Displaying the ArrayDeque
        System.out.println("ArrayDeque: " + de_que);
  
        // Creating a desc_iterator
        Iterator value = de_que.descendingIterator();
  
        // Displaying the values after iterating through the Deque
        // in reverse order
        System.out.println("The iterator values are: ");
        while (value.hasNext()) {
            System.out.println(value.next());
        }
    }
}

输出：

ArrayDeque: [10, 15, 30, 20, 5]
The iterator values are: 
5
20
30
15
10