Why can't I map integers to strings when streaming from an array?

Question

This code works (taken in the Javadoc):

List numbers = Arrays.asList(1, 2, 3, 4);
String commaSeparatedNumbers = numbers.stream()
    .map(i -         


        

Answer 1

You can create an Integer Stream using Arrays.stream(int[]) , you can call mapToObj like mapToObj(Integer::toString).

String csn = Arrays.stream(numbers) // your numbers array
.mapToObj(Integer::toString)
.collect(Collectors.joining(", "));

Hope this helps..