Last Updated : 12 Jul, 2025
The
or()method of
java.util.Optional classin Java is used to get this Optional instance if any value is present. If there is no value present in this Optional instance, then this method returns an Optional instance with the value generated from the specified supplier.
Syntax:public Optional<T> or(Supplier<T> supplier)Parameters:
This method accepts
supplieras a parameter of type T to generate an Optional instance with the value generated from the specified supplier.
Return supplier:This method returns this
Optional instance, if any value is present. If there is no value present in this Optional instance, then this method returns an Optional instance with the value generated from the specified supplier.
Exception:This method throws NullPointerException if the supplying function is null or produces a null result. Below programs illustrate or() method:
Note:As this method was added in Java 9, the programs need JDK 9 to execute.
Program 1: Java
// Java program to demonstrate
// Optional.or() method
import java.util.*;
import java.util.function.*;
public class GFG {
public static void main(String[] args)
{
// create a Optional
Optional<Integer> op
= Optional.of(9455);
// print supplier
System.out.println("Optional: "
+ op);
// or supplier
System.out.println("Optional by or(() ->"
+ " Optional.of(100)) method: "
+ op.or(() -> Optional.of(100)));
}
}
Output:
Optional: Optional[9455] Optional by or(() -> Optional.of(100)) method: Optional[9455]Program 2: Java
// Java program to demonstrate
// Optional.or() method
import java.util.*;
import java.util.function.*;
public class GFG {
public static void main(String[] args)
{
// create a Optional
Optional<Integer> op
= Optional.empty();
// print supplier
System.out.println("Optional: "
+ op);
try {
// or supplier
System.out.println("Optional by or(() ->"
+ " Optional.of(100)) method: "
+ op.or(() -> Optional.of(100)));
}
catch (Exception e) {
System.out.println(e);
}
}
}
Output:
Optional: Optional.empty Optional by or(() -> Optional.of(100)) method: Optional[100]Reference: https://docs.oracle.com/javase/9/docs/api/java/util/Optional.html#or-java.util.function.Supplier-
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