I think it converts the string to a IntStream, a stream object of the code points of each of the chars in that string? And you can use other methods on said stream object. Ex: "123".chars().toArray() gives you {49,50,51} and (char) 49 == "1".

I just tried doing this and had the same problem :o
Very glad, that Durudo posted the correct way

I agree, this was way too difficult for Kyu 6. There are Kyu 5 out there, which are significant easier than this here.