How to convert int[] into List in Java?

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How do I convert int[] into List<Integer> in Java?

Of course, I’m interested in any other answer than doing it in a loop, item by item. But if there’s no other answer, I’ll pick that one as the best to show the fact that this functionality is not part of Java.

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Streams

  1. In Java 8+ you can make a stream of your int array. Call either Arrays.stream or IntStream.of.
  2. Call IntStream#boxed to use boxing conversion from int primitive to Integer objects.
  3. Collect into a list using Stream.collect( Collectors.toList() ). Or more simply in Java 16+, call Stream#toList().

Example:

int[] ints = {1,2,3};
List<Integer> list = Arrays.stream(ints).boxed().collect(Collectors.toList());

In Java 16 and later:

List<Integer> list = Arrays.stream(ints).boxed().toList();

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