byte[] a = {1,2,3};
System.out.println(Stream.of(a).count());
Byte[] b = {1,2,3};
System.out.println(Stream.of(b).count());
the result is 1 and 3, why?
byte[] a = {1,2,3};
System.out.println(Stream.of(a).count());
Byte[] b = {1,2,3};
System.out.println(Stream.of(b).count());
the result is 1 and 3, why?
Stream.of
only accepts Objects as its arguments. A byte
isn't an Object, but a byte
array is. If a
is an array of byte
, then Stream.of(a)
can only mean "stream of this one object, which is an array".
If you have a Byte[]
array, then each element of the array is an object, so the compiler can guess that's what you mean.
There is information here about how you can stream a byte array: In Java 8, is there a ByteStream class?
For primitive arrays you should be using primitive streams, but unfortunately there is no ByteStream
. If you change your byte[]
to int[]
, you could write :
int[] a = {1,2,3};
System.out.println(IntStream.of(a).count());
Otherwise you get a Stream<byte[]>
whose single element is the input array, since both static<T> Stream<T> of(T t)
and static<T> Stream<T> of(T... values)
expect a reference type as the Stream
element, so when you pass a primitive array, the only available reference type is the array itself.
In your System.out.println(Stream.of(b).count());
case, b
is an array of reference types, so static<T> Stream<T> of(T... values)
is used to produce a Stream<Byte>
of 3 elements.