Right now I have something in php that looks like this:
$count = array_count_values($result);
arsort($count);
foreach($count as $key => $val){
$result[] = $key;
}
It will count all the items in the array and put it into a key/value pair. Which will remove the duplicates and then I tell it to sort. Then I take the key of it and store it. Is there a way to do this in Java?
I don't believe Java has an equivalent to the array_count_values function, so you will need to implement that yourself. Something like this:
public static <T> Map<T, Integer> countValues(List<T> values) {
Map<T, Integer> result = new HashMap<T, Integer>();
// iterate through values, and increment its corresponding value in result
return result;
}
Then use the java.util.Collections.sort(List list, Comparator c) function to sort the array by the counts. You'll need to implement Comparator to sort by the counts.
public class CountComparator<T> implements Comparator<T> {
private Map<T, Integer> counts;
public CountComparator(Map<T, Integer> counts) {
this.counts = counts;
}
public int compare(T o1, T o2) {
// assumes that the map contains all keys
return counts.get(o1).compareTo(counts.get(o2));
}
}
How about using a Multiset from the Google Guava library to get counts. It works in a similar way to PHP's array_count_values.
If you want it sorted by the key, then use the TreeMultiset implementation.
If you want it sorted on count, then use Multisets.copyHighestCountFirst
arsortdoesn't sort by the value in the array. It sorts by the key.