java.util.ArrayDeque.descendingIterator() 方法返回一个迭代器在此deque 队列以逆向顺序的元素。

声明

以下是java.util.ArrayDeque.descendingIterator()方法的声明

public Iterator<E> descendingIterator()

参数

• NA

返回值

此方法返回一个迭代器在此deque队列的顺序相反的元素。

异常

• NA

例子

下面的示例演示java.util.ArrayDeque.descendingIterator()方法的用法。

package com.yiibai;

import java.util.ArrayDeque;
import java.util.Deque;
import java.util.Iterator;

public class ArrayDequeDemo {
   public static void main(String[] args) {
      
     // create an empty array deque with an initial capacity
     Deque<Integer> deque = new ArrayDeque<Integer>(8);

     // use add() method to add elements in the deque
     deque.add(15);
     deque.add(22);
     deque.add(25);
     deque.add(20);

     //iterator() is used to print all the elements
     //next() returns the next element on each iteration
     System.out.println("printing elements using iterator:");
	 
     for(Iterator itr = deque.iterator();itr.hasNext();)  {
        System.out.println(itr.next());
     }

     //descendingIterator() is used to print the elements in reverse order
     //next() returns the next element on each iteration
     System.out.println("printing elements in reverse order:");
	 
     for(Iterator descItr = deque.descendingIterator();descItr.hasNext();) {
        System.out.println(descItr.next());
     }
   }
 }  

让我们来编译和运行上面的程序，这将产生以下结果：

printing elements using iterator:
15
22
25
20
printing elements in reverse order:
20
25
22
15