CODEWITHSUNDEEP
javahashmap
serra gengec
serra gengec

Reputation: 1

how can I change a value indside a map of maps?

I have a map of a string and a map, and I want to change a value inside the inner map but I couldn't find a method to do that. How can I reach and change the specific value inside the inner map?

here's my maps:

String teamName;

Map<String, Integer> players = new HashMap<String,Integer>();   

Map<String, Map> teams = new HashMap<String, Map>();

teams.put(teamName, players);

I want to increase or decrease this integer value inside the players map from the teams map. But I cannot use the players map directly because of the rest of my code, I need to reach it from the teams map.

Upvotes: 0

Views: 77

Answers (2)

ΦXocę 웃 Пepe&#250;pa ツ
ΦXocę 웃 Пepe&#250;pa ツ

Reputation: 48258

with the map put and get can be tricky, you should define yyour own class, but this is ans example of what you are asking:

Map<String, Integer> players = new HashMap<>();
Map<String, Map<String, Integer>> teams = new HashMap<>();

players.put("Podolski", 0);
players.put("mueller", 0);

teams.put("BayernMuc", players);

System.out.println(players);
System.out.println(teams);
int goals = teams.get("BayernMuc").get("mueller");
teams.get("BayernMuc").put("mueller", 5);

System.out.println(teams);
goals = teams.get("BayernMuc").get("mueller");
teams.get("BayernMuc").put("mueller", ++goals);
System.out.println(players);
System.out.println(teams);

Upvotes: 0

ernest_k
ernest_k

Reputation: 45319

All you need to do is access the appropriate team's map, then set the number.

It will help if you used generics throughout:

String teamName = "someteam";
Map<String, Integer> players = new HashMap<String,Integer>();   
Map<String, Map<String, Integer>> teams = new HashMap<String, Map<String, Integer>>();
teams.put(teamName, players);

And to change the number of players in team with teamName as key:

teams.get(teamName).put("somename", 123);
//Or to directly overwrite with an increment:
int currentValue = teams.get(teamName).get("somename");
teams.get(teamName).put("somename", currentValue + 1);

Upvotes: 1

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