Why isn't this lambda a singular object?

Question

Simply, I'm trying to iterate over an array using a stream to find out if every element is the same type of object. I have figured out two ways of doing this (foo is a byte array byte[]).

Arrays.asList(foo).parallelStream().allMatch(aByte -> aByte == Byte.MIN_VALUE);

and

Stream.of(foo).parallel().allMatch(aByte -> aByte == Byte.MIN_VALUE);

However, I keep getting the error "Incompatible operand types byte[] and byte". So that means that aByte is of type byte[]. Why is that? Why is it not just a normal byte? And how may I correct this problem?

They have `IntStream.of(int...)`, but there's no `ByteStream` :) ... — ZhongYu, Sep 04 '15 at 19:59

score 4 · Accepted Answer · edited May 23 '17 at 12:14

If foo is of type byte[], then Arrays.asList(foo) will return a list containing a single element: foo.

It would return a list containing all the elements of foo is foo was an array of Objects. But it's not, because byte is a primitive type, not an Object. And a byte[] is thus not an Object[].

What you should use in fact is an IntStream. See What is the best way to convert a byte array to an IntStream? for how to convert a byte array to an IntStream.

Note that using a parallel stream for such a simple task is not a good idea. Unless the byte array is awfully huge and contains only Byte.MIN_VALUE, the overhead of a parallel stream over a sequential one will make things slower.

Why isn't this lambda a singular object?

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