/Java/Group all keys with same values in a hashmap java

Group all keys with same values in a hashmap java

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

for (Map.Entry<Integer,String> entry : map.entrySet()) {
    if (!reverseMap.containsKey(entry.getValue())) {
        reverseMap.put(entry.getValue(), new ArrayList<>());
    }
    ArrayList<Integer> keys = reverseMap.get(entry.getValue());
    keys.add(entry.getKey());
    reverseMap.put(entry.getValue(), keys);
}

Source: stackoverflow.com

Similar codes

0 vote212 views1 answer
What is import java.io.*?
Java
1 vote207 views2 answers
Android studio keep device awake
Java
10 votes192 views3 answers
How to change default port in spring boot
Java
0 vote196 views1 answer
Java program to find largest of three numbers using nested if
Java
8 votes201 views4 answers
Char to ascii java
Java
2 votes191 views1 answer
Get instance of object java
Java
0 vote204 views1 answer
Public static void trong java là gì
Java
22 votes187 views1 answer
How to exit a java program
Java
0 vote190 views1 answer
Algorithms - transformation
Java
0 vote191 views1 answer
What is the import for gogga class java
Java