如何迭代Hashmap中的元素？

我想制作一个Java游戏。 首先，程序会询问玩家的数量; 之后，它要求他们的名字。 我把他们的名字放在一个带有ID及其分数的HashMap 。 在游戏结束时，我计算得分，我想把它放在HashMap （具体名称的具体分数）。 有谁知道如何做到这一点？ 这是我的代码：

玩家：

 public class Player { public Player() { } public void setScore(int score) { this.score = score; } public void setName(String name) { this.name = name; } private String name; private int score; public Player(String name, int score) { this.name = name; this.score = score; } public String getName() { return name; } @Override public String toString() { return "Player{" + "name=" + name + "score=" + score + '}'; } public int getScore() { return score; } 

主要：

 Scanner scanner = new Scanner(System.in); HashMap name= new HashMap(); System.out.printf("Give the number of the players "); int number_of_players = scanner.nextInt(); for(int k=1;k<=number_of_players;k++) { System.out.printf("Give the name of player %d: ",k); name_of_players= scanner.nextLine(); name.put(k, new Player(name_of_players,0));//k=id and 0=score } //This for finally returns the score and for(int k=1;k<=number_of_players;k++) { Player name1 = name.get(k); System.out.print("Name of player in this round:"+name1.getName()); .............. ............. int score=p.getScore(); name.put(k,new Player(name1.getName(),scr));//I think here is the problem for(int n=1;n<=number_of_players;n++)//prints all the players with their score { System.out.print("The player"+name1.getName()+" has "+name1.getScore()+"points"); } 

有谁知道我怎么能最终打印例如：

 "The player Nick has 10 points. The player Mary has 0 points." 

更新：

我主要是这样做的（正如Jigar Joshi建议的那样）

  name.put(k,new Player(name1.getName(),scr)); Set<Map.Entry> set = name.entrySet(); for (Map.Entry me : set) { System.out.println("Score :"+me.getValue().getScore() +" Name:"+me.getValue().getName()); } 

它打印“得分：0名称：得分：4名称：a”当我把两个名字的玩家“a”和“b”。我认为问题在这里

  name.put(k,new Player(name1.getName(),scr)); 

如何将名称放在我之前的“names_of_players”中？

Answer 1

在迭代中需要关键和价值

使用entrySet()迭代Map并需要访问value和key：

 Map hm = new HashMap(); hm.put("A", new Person("p1")); hm.put("B", new Person("p2")); hm.put("C", new Person("p3")); hm.put("D", new Person("p4")); hm.put("E", new Person("p5")); Set> set = hm.entrySet(); for (Map.Entry me : set) { System.out.println("Key :"+me.getKey() +" Name : "+ me.getValue().getName()+"Age :"+me.getValue().getAge()); } 

需要重点迭代

如果你只想迭代地图的keys ，你可以使用keySet()

 for(String key: map.keySet()) { Person value = map.get(key); } 

在迭代中需要价值

如果您只想迭代map的values ，可以使用values()

 for(Person person: map.values()) { } 

Answer 2

你不应该将得分映射到玩家。 你应该将球员（或他的名字）映射到得分：

Map player2score = new HashMap();

然后添加玩家到map：int score = ….玩家玩家=新玩家（）; player.setName（ “约翰”）; //等等player2score.put（玩家，得分）;

在这种情况下，任务是微不足道的：

int score = player2score.get(player);

Answer 3

由于所有玩家都被编号，我只会使用ArrayList()

就像是

 List players = new ArrayList(); System.out.printf("Give the number of the players "); int number_of_players = scanner.nextInt(); scanner.nextLine(); // discard the rest of the line. for(int k = 0;k < number_of_players; k++){ System.out.printf("Give the name of player %d: ", k + 1); String name_of_player = scanner.nextLine(); players.add(new Player(name_of_player,0)); //k=id and 0=score } for(Player player: players) { System.out.println("Name of player in this round:" + player.getName()); 

Answer 4

 HashMap hash = new HashMap(); Set keys = hash.keySet(); Iterator itr = keys.iterator(); while(itr.hasNext()){ Integer key = itr.next(); Player objPlayer = (Player) hash.get(key); System.out.println("The player "+objPlayer.getName()+" has "+objPlayer.getScore()+" points"); } 

您可以使用此代码以您的格式打印所有分数。