The Stream.reduce Method
//The following pipeline uses the Stream.reduce operation to calculate the sum
//of the male members' ages in the collection roster:
Integer totalAgeReduce = roster
.stream()
.map(Person::getAge)
.reduce(
0,
(a, b) -> a + b);
- The Stream.reduce method is a general-purpose reduction operation.
- The reduce operation may take two arguments: identity and accumulator.
- The reduce operation always returns a new value.