Java 8 :: Snippet 1 :: Compute product of even numbers (streams, lambda expressions, type inference, filters, reducers and optional type)

java8_snippet1.java

// Compute product of even numbers
OptionalInt r = Streams.intRange(1, 11) // [1..10]
  .filter(n -> n % 2 == 0)
  .reduce((acc, n) -> acc * n);
out.println(r.isPresent() ? r.getAsInt() : 1);