Counting elements of a Stream

Question

I want to count the different elements of a stream and am wondering why

Stream stream = Stream.of(\"a\", \"b\", \"a\", \"c\", \"c\", \"a\", \"a         


        

Answer 1

    private Collector customIntegerCountingCollector() {
    return Collector.of(
        () -> new int[1],
        (result, ) -> result[0] += 1,
        (result1, result2) -> {
            result1[0] += result2[0];
            return result1;
        },
        total -> Integer.valueOf(total[0])
    );
}

Inspired by : https://www.deadcoderising.com/2017-03-07-java-8-creating-a-custom-collector-for-your-stream/