How to sort a HashMap into a leaderboard.

[Canada_]

How would you sort a hashmap into a leaderboard of top 10?
Please leave ideas.

 

[kev626]

Make the keys or values comparables, put the entire keyset into a list, and use Collections.sort() to sort it.

It is impossible to sort a hashset or a hashmap, you may want to consider using a different datastructure if you wish to sort it.

 

[kampai]

Java 8

    public List<PlayerFaction> getTopFactions(int i) {
        return playerFactions().stream().sorted(Comparator.comparingInt(PlayerFaction::getOnlineSize)).limit(i).collect(Collectors.toList());
    }

If you used parallel it'd be pretty nice

 

[Bryce]

I'd suggest using a TreeMap. A TreeMap implements a SortedMap and NavigatableMap. This means, when items are added to the TreeMap, they will hold their natural order. A HashMap however, you cannot guarantee the map will hold its order. Essentially, If you are sorting, it is highly suggested that you use a TreeMap as the order will be pure and entirely up to you on how its sorted.

 

[Canada_]

I'd suggest using a TreeMap. A TreeMap implements a SortedMap and NavigatableMap. This means, when items are added to the TreeMap, they will hold their natural order. A HashMap however, you cannot guarantee the map will hold its order. Essentially, If you are sorting, it is highly suggested that you use a TreeMap as the order will be pure and entirely up to you on how its sorted.

Thank you