What is Optional class in java?

Inspired from Haskell and Scala, Java SE 8 introduces a new class in util package, java.util.Optional, whose instance hold an object so that it either contains a value or not (empty). It eliminates NullPointerException and the null check constructs.

Example of an empty optional:

Optional<String>  str= Optional.empty();

Optional non-empty object:

String str = "javapedia.net";

Optional<String> oStr = Optional.of(str);

 public static void main(String[] args) {
        Optional<String> emptyO = Optional.empty();
        System.out.println(emptyO);
        System.out.println(emptyO.isPresent());
        System.out.println(emptyO.orElseGet(()->"AssignThisIfEmpty"));
        Optional<String> strO = Optional.of("javapedia.net");
        System.out.println(strO);
        System.out.println(strO.isPresent());
        System.out.println(strO.get());

    }

Output:

Optional.empty
false
AssignThisIfEmpty
Optional[javapedia.net]
true
javapedia.net

Invest now in Acorns!!! 🚀
Join Acorns and get your $5 bonus!

Acorns is a micro-investing app that automatically invests your "spare change" from daily purchases into diversified, expert-built portfolios of ETFs. It is designed for beginners, allowing you to start investing with as little as $5. The service automates saving and investing. Disclosure: I may receive a referral bonus.

Invest now!!! Get Free equity stock (US, UK only)!

Use Robinhood app to invest in stocks. It is safe and secure. Use the Referral link to claim your free stock when you sign up!.

The Robinhood app makes it easy to trade stocks, crypto and more.

Webull! Receive free stock by signing up using the link: Webull signup.