// streams/OptionalsFromEmptyStreams.java

// (c)2020 MindView LLC: see Copyright.txt

// We make no guarantees that this code is fit for any purpose.

// Visit http://OnJava8.com for more book information.

import java.util.*;

import java.util.stream.*;

class OptionalsFromEmptyStreams {

public static void main(String[] args) {

System.out.println(Stream.<String>empty()

.findFirst());

System.out.println(Stream.<String>empty()

.findAny());

System.out.println(Stream.<String>empty()

.max(String.CASE_INSENSITIVE_ORDER));

System.out.println(Stream.<String>empty()

.min(String.CASE_INSENSITIVE_ORDER));

System.out.println(Stream.<String>empty()

.reduce((s1, s2) -> s1 + s2));

System.out.println(IntStream.empty()

.average());

}

}

/* Output:

Optional.empty

Optional.empty

Optional.empty

Optional.empty

Optional.empty

OptionalDouble.empty

*/