LongStream reduce(LongBinaryOperator op) example
Description
LongStream reduce(LongBinaryOperator op) performs a reduction on the elements of this stream, using an associative accumulation function, and returns an OptionalLong describing the reduced value, if any.
Syntax
reduce has the following syntax.
OptionalLong reduce(LongBinaryOperator op)
Example
The following example shows how to use reduce.
import java.util.OptionalLong;
import java.util.stream.LongStream;
//from w w w . ja va2s .c o m
public class Main {
public static void main(String[] args) {
LongStream b = LongStream.of(1L, 2L, 3L, 4L);
OptionalLong v = b.reduce(Long::sum);
if(v.isPresent()){
System.out.println(v.getAsLong());
}else{
System.out.println("no value");
}
}
}
The code above generates the following result.
