Java 8 Features - General Questions

Which date-time class (java.time) represents a date without time?

Which stream operation is terminal?

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        java.util.Optional<String> o = java.util.Optional.empty();
        System.out.println(o.orElse("none") + " " + o.isPresent());
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        System.out.println(java.util.stream.IntStream.rangeClosed(1, 4).reduce(1, (a, b) -> a * b));
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        var words = java.util.List.of("a", "bb", "cc", "ddd");
        var g = words.stream().collect(java.util.stream.Collectors.groupingBy(String::length, java.util.stream.Collectors.counting()));
        System.out.println(g);
    }
}