如何一次又一次地使用相同的迭代器？

问题描述

给出下一个代码：

//这是某个大方法的一部分//

  ArrayList< String> players = this.m_maze.getPlayers（）; 
 
 //将第一个节点定义为人类玩家，并从列表中弹出他
 //其余节点是计算机端
 
 Iterator< ;字符串> iterator = players.iterator（）; 
 
 //人类边
字符串humanPlayer = iterator.next（）; 
 
 
 //控制器 - 在玩家之间开始游戏，至少有两名玩家玩
而（this.m_rounds> 0）
 {
 
 
 String [] choices = this.m_view.getChoiceFromUser（）; 
 
 int usersChoice = Integer.parseInt（choices [0]）; 
 
开关（usersChoice）
 {
案例1：//然后用户选择保留
 {
 
} 
 
案例2：//然后采取下一步
 {
 //让用户移动
 
 this.m_maze = this.m_model.makeSomeMove（选择[1]，humanPlayer，TRUE）; 
 
 //打印迷宫以进行可视化
 this.m_view.drawMaze（m_maze）; 
 
 //控制器 - 减少当前游戏的当前回合数
 this.m_rounds--; 
} 
 
案例31：//然后用户要求最近的宝贝
 {
 //稍后在
上放一些代码} 
 
 
案例32：//然后用户要求最近的房间
 {
 //稍后在
放置一些代码} 
 
} //结束开关盒
 
} //结束时
  

（ 1）。每次调用 makeSomeMove 后，我如何在 humanPlayer 中放置ArrayList的第一个元素？ / p>

（2）。是否可以重用迭代器？因为我使用 hasnext（）和 next（） ...？

非常感谢
Ron

解决方案

如果你想要要重用迭代器，你必须重新初始化它。

你必须执行 Iterator< String> iterator = players.iterator（）; 每当你想重用迭代器时。

Given the next code :

// this is a part of some large method //

        ArrayList<String> players = this.m_maze.getPlayers();

    // define the first node to be the human player , and pop him from the list
    // the rest of the nodes are the computer side

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

    // human side
    String humanPlayer = iterator.next();


    // controller - start a game between the players , at least two players are playing
    while (this.m_rounds > 0)
    {


        String[] choices = this.m_view.getChoiceFromUser();

        int usersChoice = Integer.parseInt(choices[0]);

        switch (usersChoice)
        {
            case 1:   // then user chose to stay put
            {

            }

            case 2:   // then take the next step
            {
                // let the user make his move

                this.m_maze = this.m_model.makeSomeMove(choices[1],humanPlayer,true);

                // print out the maze for visualization
                this.m_view.drawMaze(m_maze);

                // controller - reduce the number of current rounds for the current game
                this.m_rounds--;
            }

            case 31:   // then user asked for the closest treasure
            {
                //  put some code here later on
            }


            case 32:   // then user asked for the nearest room
            {
            //  put some code here later on
            }

        }  // end switch case

    } // end while

(1).How can I place in humanPlayer the first element of the ArrayList after each time that I invoke makeSomeMove ?

(2).Is it possible to reuse an iterator ? since I use the hasnext() and next() ... ?

Many thanksRon

解决方案

If you want to reuse the iterator, you have to re-initialise it.

You have to execute Iterator<String> iterator = players.iterator(); whenever you want to reuse the iterator.

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