How to use Lambda functions to de-sign Java's signed bytes?

Question

Extending from converting an array of signed bytes to unsigned bytes, can this be performed more elegantly without the clunky for loop using Lambdas? So,

signed byte[] -> unsigned int[]

I note that there is no Arrays.stream(byte[]).

Java has a [`Byte.toUnsignedInt`](https://docs.oracle.com/javase/8/docs/api/java/lang/Byte.html#toUnsignedInt-byte-). Honestly, I think `Stream` is a bit of overkill and a `for` loop is more elegant. — M. le Rutte, May 20 '18 at 15:48

score 0 · Answer 1 · answered May 20 '18 at 15:33

0

Sure, you can:

int[] unsigned = IntStream.range(0, signed.length)
                          .map(i -> signed[i] & 0xFF)
                          .toArray();

where signed represents the array of bytes.

answered May 20 '18 at 15:33

Ousmane D.

54,915
8
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score 0 · Answer 2 · answered May 20 '18 at 15:34

Yes, you could achieve it using IntStream:

public static int[] toUnsignedIntArray(byte[] array) {
    return IntStream.range(0, array.length)
                    .map(idx -> array[idx] &  & 0xFF)
                    .toArray();
}

For more information, see this answer.

score 0 · Answer 3 · answered May 20 '18 at 15:38

0

You could do it like this.

int[] unsigned = IntStream.range(0, bytes.length)
                          .map(i -> 0x7F & bytes[i])
                          .toArray();

answered May 20 '18 at 15:38

Bruno L

839
5
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How to use Lambda functions to de-sign Java's signed bytes?

3 Answers3