find the frequency of elements in a java array

Question

I have an int array:

{1,2,4,2,3,5,6,4,3}

How can I find frequencies of array elements like 1=1,2=2,3=2,4=4... I need a class w

Answer 1

Using Java-8 we can find the frequency of an array in a single line.

Map freq = Arrays.stream(a).boxed().
                          collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));

Also, since the question demands we need to return an array

public Object[] getFrequencies(int[] a) {
    Map freq = Arrays.stream(a).boxed().collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
    return freq.entrySet().toArray();
}