DaftLeech :
int[] ar1 = {1,2,3};
int[] ar2 = {1,2,3};
Output:
{2,3,4,3,4,5,4,5,6}
I tried something like this:
IntStream.range(0,ar1.length).map(x -> IntStream.range(0,ar2.length).map(y -> ar1[y]+ar2[x]));
but this does not work:
Type mismatch: cannot convert from
IntStreamtoint.
How can I sum every value of ar1 with every value of ar2 in Java 8 using streams?
Eran :
You should use flatMap, since map of IntStream is expected to map each int element of the original IntStream to an int, not to an IntStream.
System.out.println(Arrays.toString (
IntStream.range(0,ar1.length)
.flatMap(x -> IntStream.range(0,ar2.length).map(y -> ar1[x]+ar2[y]))
.toArray ()));
Output:
[2, 3, 4, 3, 4, 5, 4, 5, 6]
As an alternative to creating an IntStream of the indices of the array, you can create an IntStream of the elements of the array:
System.out.println(Arrays.toString (
Arrays.stream(ar1)
.flatMap(x -> Arrays.stream(ar2).map(y -> x + y))
.toArray ()));
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