java.util.ArrayDeque.descendingIterator() 方法返回一個迭代器在此deque 隊列以逆向順序的元素。

聲明

以下是java.util.ArrayDeque.descendingIterator()方法的聲明

public Iterator<E> descendingIterator()

參數

• NA

返回值

此方法返回一個迭代器在此deque隊列的順序相反的元素。

異常

• NA

例子

下麵的示例演示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());
     }
   }
 }  

讓我們來編譯和運行上麵的程序，這將產生以下結果：

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