Java tutorial
import java.util.OptionalDouble; import java.util.stream.DoubleStream; public class Main { public static void main(String[] args) { DoubleStream d = DoubleStream.of(1.2, 2.3, 4.5); OptionalDouble v = d.average(); if (v.isPresent()) { System.out.println(v.getAsDouble()); } else { System.out.println("no value"); } } }