Java 11 introduced new method to Optional class as isEmpty() to check if value is present. isEmpty() returns false if value is present otherwise true.
It can be used as an alternative of isPresent() method which often needs to negate to check if value is not present.
Consider the following program −
Java11Optional.java
import java.util.Optional;
public class Java11Optional {
public static void main(String[] args) {
// 1. Check non-null value is present
String name = "Elavarasan";
System.out.println(Optional.ofNullable(name).isPresent());
System.out.println(Optional.ofNullable(name).isEmpty());
// 2. Check string has null/empty value
name = null;
System.out.println(Optional.ofNullable(name).isPresent());
System.out.println(Optional.ofNullable(name).isEmpty());
}
}
Output:
true
false
false
true