Java.util.ArrayDeque.descendingIterator()

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描述

所述java.util.ArrayDeque.descendingIterator()方法返回一个迭代器可在此元素双端队列以逆向顺序。

声明

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

public Iterator<E> descendingIterator()

参数

NA

返回值

此方法以相反的顺序返回此双端队列中元素的迭代器。

异常

NA

实例

以下示例显示了java.util.ArrayDeque.descendingIterator()方法的用法。

package com.tutorialspoint;

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());
      }
   }
 }

让我们编译并运行上面的程序,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