Java stream reduce to map

Question

I got array list of strings, how could I reduce them to hash map

Input: [a, b, a, a, c, x]

Output: {(a: 3), (b: 1), (c: 1), (x: 1)}

PS. I searched for this. I need to do that with reduce not with frequency counting as in other questions, because my question is a simplified real task.

Answer 1

Thanks @HadiJ for answer

Map<String,Integer> result = Arrays.stream(str)
    .reduce(
        new HashMap<>(),
        (hashMap, e) -> {
            hashMap.merge(e, 1, Integer::sum);
            return hashMap;
        },
        (m, m2) -> {
            m.putAll(m2);
            return m;
        }
    );