Stream displaing the result

Question

How can I display result Stream<int[]> allResults = list.stream();

I try:

allResluts.forEach(System.out::println);

score 3 · Answer 1 · answered Mar 25 '19 at 20:17

3

You should use Arrays.toString for printing array:

stream.forEach(ints -> System.out.println(Arrays.toString(ints)));

answered Mar 25 '19 at 20:17

Ruslan

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score 1 · Answer 2 · edited Mar 25 '19 at 20:24

1

Looking at this line:

Stream<int[]> allResults = list.stream();

It means, that every element of stream is an array, you might do this:

allResults.flatMap(a -> Arrays.stream(a).mapToObj(Integer::valueOf)).forEach(System.out::println);

or, as @YCF_L suggests, even simplier:

allResults.flatMap(Stream::of).forEach(System.out::println);

edited Mar 25 '19 at 20:24

YCF_L

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answered Mar 25 '19 at 20:17

Andronicus

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not down-voter but `int` not `Integer` you need boxed – YCF_L Mar 25 '19 at 20:20
just replace `.flatMap(Arrays::stream)` with `.flatMap(Stream::of)` – YCF_L Mar 25 '19 at 20:22
or `flatMapToInt` – Ruslan Mar 25 '19 at 20:22
Yes, you're right. Thanks guys for suggestions:) – Andronicus Mar 25 '19 at 20:24
1

I don't think he talks about arrays of arrays at all. I mean from his initialization it could be said so, but his implementation speaks otherwise and assuming his level of Java, I would think he meant just printing an array of numbers using streams. – MS90 Mar 25 '19 at 20:26
@MS90 you might be right, but I'll try to use given code, not the assumptions;) – Andronicus Mar 25 '19 at 20:29

MS90 · Answer 3 · 2019-03-25T21:04:06.347

Well, you can do something like following:

int[] numbers = {2,4,7,4,3,6};
IntStream.of(numbers).forEach(System.out::print);

UPDATE:

If you have int[][] like some suggests, use following code:

int[][] numbersOfNumbers = {{1, 25, 63}, {4}, {42, 53},{3,6,4,7,3}};
//same as above with int[][]
Stream.of(numbersOfNumbers).flatMap(Stream::of).forEach(i->IntStream.of(i).forEach(System.out::print));
Stream.of(numbersOfNumbers).flatMap(Stream::of).forEach(numbs->System.out.println(Arrays.toString(numbs)));

Stream displaing the result

3 Answers3