Optional Class

In Java, the Optional class was introduced in Java 8 to handle null values and avoid NullPointerExceptions. It provides a way to encapsulate an optional value.

To create an Optional object, you can use the static methods of() and ofNullable(). The of() method expects a non-null value, while the ofNullable() method can accept both null and non-null values.

Here's an example:

1import java.util.Optional;
2
3public class Main {
4
5    public static void main(String[] args) {
6        String name = null;
7        Optional<String> optionalName = Optional.ofNullable(name);
8
9        if (optionalName.isPresent()) {
10            System.out.println("Name: " + optionalName.get());
11        } else {
12            System.out.println("Name is not present");
13        }
14    }
15
16}

In this example, we have a variable name that is null. We create an Optional object, optionalName, using the ofNullable() method. We can then use the isPresent() method to check if a value is present in the Optional object, and the get() method to retrieve the value.

If the value is present, we print it as "Name: [value]", otherwise, we print "Name is not present".

By using the Optional class, we can handle null values more gracefully and avoid NullPointerExceptions. It encourages a more explicit and safer coding style by forcing the developer to check for the presence of a value before using it.

xxxxxxxxxx

import java.util.Optional;

​

public class Main {

​

    public static void main(String[] args) {

        String name = null;

        Optional<String> optionalName = Optional.ofNullable(name);

        if (optionalName.isPresent()) {

            System.out.println("Name: " + optionalName.get());

        } else {

            System.out.println("Name is not present");

        }

    }

​

}