Question

如何反向迭代ArrayDeque？

我通常会为数组执行此操作，但它不可编入索引。

for (int i = delegate.size() - 1; i >= 0; i--) {}

感谢

Answer 1

您可以使用方法descendingIterator()来获取迭代迭代ArrayDeque的迭代器。

Iterator it = arrayDeque.descendingIterator();
while(it.hasNext())
{
    // do something with it.next()
}

Answer 2

试试这个

元素将从倒数第一个以相反的顺序返回。

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */

class List {
   public static void main(String[] args) {
      // creating a TreeSet 
      TreeSet <Integer>treeadd = new TreeSet<Integer>();

      // adding in the tree set
      treeadd.add(1);
      treeadd.add(13);
      treeadd.add(17);
      treeadd.add(2);

      // create descending iterator
      Iterator iterator;
      iterator = treeadd.descendingIterator();

      // displaying the Tree set data
      System.out.println("Descending order: ");     
      while (iterator.hasNext()){
          System.out.println(iterator.next() + " ");
      }
   }    
}

我怎样才能反向迭代ArrayDeque？

2 个答案: