Question

I have 2 arrays String key[] , long value[] . keys can be duplicated . I need unique keys and their sum of the values in a map. Below is the code I am trying but i get Array out of bound exception

public HashMap < String, Long > getValueMap(String key[], long value[]) {
    Map newmap = new HashMap();
    long count = 0;
    for (int i = 0; i < value.length; i++) {
        for (int j = 0; j < value.length; j++) {
            if (key[i] == key[j]) {
                count = count + value[j];
            }
        }
        newmap.put(key[i], count);

        count = 0;
    }
    return (HashMap < String, Long > ) newmap;

}


long[] value = {};
String key[] = {};
int i = 0;
        if(!worklogs.isEmpty()){
            for(Worklog wl:worklogs){
                value[i]=wl.getValue();
                key[i]=wl.getAuthor();i++;

            }
        }

HashMap < String, Long > newhm = getValueMap(key, value);
Iterator entries = newhm.entrySet().iterator();
while (entries.hasNext()) {
    Map.Entry entry = (Map.Entry) entries.next();
    String newkey = (String) entry.getKey();
    Long newvalue = (Long) entry.getValue();
    System.out.println("Key = " + newkey + ", Value = " + newvalue);
}

The above code is modified to make it look simple. Please can someone help ?

Answer 1

This may be caused because arrays value and key haven’t been initialized before trying to add values to them.

long[] value= new long[10];

String key[]= new String[10];

Why do you need to use arrays instead of Lists? Because if you need the length to ve variable I think it would be a more comfortable approach.