重新初始化ArrayList的迭代器不起作用

Question

鉴于以下情况：

    // get the list of the players , in order to start the game 
    ArrayList<String> players = this.m_maze.getPlayers();
    // human side 
    String humanPlayer = iterator.next();
    String computerPlayer = null;
    // define iterator for the players 

    Iterator<String> iterator = players.iterator();     
    boolean humanSide = true ,computerSide = false;    // assume the human player is starting the game 


    // controller - start a game between the players , at least two players are playing 

    while (this.m_rounds > 0)  
    {

        if (humanSide == false && computerSide == true) // then this is the turn of the human side 
        {
            if (iterator.hasNext() == false)
            {
                // reinitialize the iterator
                Iterator<String> iterator = players.iterator();

            }
            while (iterator.hasNext())


                        // more code 

我尝试重用迭代器，但出现“重复局部变量迭代器”编译错误。我如何重用该迭代器？ 谢谢，罗恩

编辑：

            if (iterator.hasNext() == false)
            {
                // reinitialize the iterator
                iterator = players.iterator();

            }
            while (iterator.hasNext())
            {
                computerPlayer = iterator.next();

                // computer decides what would be his next move , between 1 - 3 

Answer 1

不要重新声明变量；只需分配它即可。

if (iterator.hasNext() == false) {
    iterator = players.iterator();
}

您应该小心嵌套循环行为。您的真正意图是让以下块

while (iterator.hasNext()) { ... }

实际检查这种情况吗？

while (iterator.hasNext() && (this.m_rounds > 0)) { ... }

Answer 2

您已将 Iterator; iterator =players.iterator(); 在你的循环中。

所以每次它尝试创建名为iterator的变量。

只需将其声明放在循环之外...就像

 Iterator<String> iterator;     //here ****
 while (this.m_rounds > 0)  
   {

    if (humanSide == false && computerSide == true) // then this is the turn of the human side 
    {
        if (iterator.hasNext() == false)
        {
            // reinitialize the iterator
            iterator = players.iterator();

        }
        while (iterator.hasNext())

Answer 3

我认为 google guava 几乎可以满足您的需求 Iterators#cycle。

像这样使用它：

    Iterator<String> iterator = Iterators.cycle(players.iterator());

......你永远不会用完玩家。

Answer 4

不要使用这样的迭代器，它会把事情搞砸，就用老方法吧，我的意思是使用著名的迭代器先生“i”。而且代码看起来会更合理。

    while(m_rounds > 0){

        if(i == players.size()) {
            i = 0;
        }

        currentPlayer = players.get(i);

        //Do what you want to do with the current player...

        ...

        //Next
        i++;


    }

一个小建议，您真的需要两个标志吗，我的意思是 humanSide 和 ComputerSide？只用一个就够了吗？你的 if-else 块看起来会更加简单和清晰：

if(humanSide) {

   //Hope this move wouldn't crush your logic.

} else {

  //Algorithm based awesome move.

}

Answer 5

好的，只需删除 Iterator ，意思是，当重用该迭代器时只需编写： iterator =players.iterator();

谢谢大家！