Is something wrong with the method? [closed]

Solution 1:

Where is 'partners' coming from? You're running a for loop on it. Did you mean aSuspect?

If you are getting multiple of the same value. Do a check on the arraylist before adding it.

public ArrayList<Suspect> getCommonPartners(Suspect aSuspect) {
ArrayList<Suspect> commonpartners = new ArrayList<>() ;
    for(Suspect s: partners) {
        for(Suspect sus: aSuspect.getPartners()) {
            if(s.getCodename().equals(sus.getCodename())) {
                if(!commonpartners.contains(s)) {
                    commonpartners.add(s);
                  }
            }
        }
    }
    return (commonpartners);
}