I'm creating a console game in Java. And I want to keep track of the scores and names.
I've already created two arrays.
String[] PlayerNames = {"Bob", "Rick", "Jack"}; // just an example
int[] PlayerScores = {40, 20, 60}; // just an example
I want to sort their scores, but also know who the score belongs to, and then print it out like this:
Jack 60
Bob 40
Rick 20
Create a map with the player names as the keys and the scores as the values, then sort the map based on the values:
public static void main(String[] args) {
Map<String, Integer> unsortedMap = new HashMap<String, Integer>();
unsortedMap.put("Jack", 60);
unsortedMap.put("Bob", 40);
unsortedMap.put("Rick", 20);
Map<String, Integer> sortedMap = sortByValue(unsortedMap);
printMap(sortedMap);
}
private static Map<String, Integer> sortByValue(Map<String, Integer> unsortMap) {
// 1. Convert Map to List of Map
List<Map.Entry<String, Integer>> list =
new LinkedList<Map.Entry<String, Integer>>(unsortMap.entrySet());
// 2. Sort list with Collections.sort(), provide a custom Comparator
// Try switch the o1 o2 position for a different order
Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {
public int compare(Map.Entry<String, Integer> o1,
Map.Entry<String, Integer> o2) {
return (o1.getValue()).compareTo(o2.getValue());
}
});
// 3. Loop the sorted list and put it into a new insertion order Map LinkedHashMap
Map<String, Integer> sortedMap = new LinkedHashMap<String, Integer>();
for (Map.Entry<String, Integer> entry : list) {
sortedMap.put(entry.getKey(), entry.getValue());
}
/*
//classic iterator example
for (Iterator<Map.Entry<String, Integer>> it = list.iterator(); it.hasNext(); ) {
Map.Entry<String, Integer> entry = it.next();
sortedMap.put(entry.getKey(), entry.getValue());
}*/
return sortedMap;
}
public static <K, V> void printMap(Map<K, V> map) {
for (Map.Entry<K, V> entry : map.entrySet()) {
System.out.println("Key : " + entry.getKey()
+ " Value : " + entry.getValue());
}
}
Note: see https://www.mkyong.com/java/how-to-sort-a-map-in-java/ for more details.
You can use a hashmap for this. Use each name from playerNames as a key and create a list for the values (in case two or more players with the same name get a score). A hashmap allows only one value per key, which is why you should create a list of integers for the scores.
Map<String, List<Integer>> scoreboard = new HashMap<>();
