OptionalDouble help us to create an object which may or may not contain a Double value. The orElseThrow() method help us to get the double value. If double value is not present then this method will throw NoSuchElementException. Syntax:
public Double orElseThrow()
Parameters: This method accepts nothing. Return value: This method returns the Double value described by this OptionalDouble. Exception: This method throws NoSuchElementException if no value is present Below programs illustrate orElseThrow() method: Program 1:Â
Java
// Java program to demonstrate// OptionalDouble.orElseThrow() methodÂ
import java.util.OptionalDouble;Â
public class GFG {Â
    public static void main(String[] args)    {Â
        // create a OptionalDouble        OptionalDouble opDouble            = OptionalDouble.of(134.1);Â
        // get value using orElseThrow()        System.out.println("double Value extracted using"                           + " orElseThrow() = "                           + opDouble.orElseThrow());    }} |
Output:
double Value extracted using orElseThrow() = 134.1
Program 2:Â
Java
// Java program to demonstrate// OptionalDouble.orElseThrow() methodÂ
import java.util.OptionalDouble;Â
public class GFG {Â
    public static void main(String[] args)    {Â
        // create a OptionalDouble        OptionalDouble opDouble            = OptionalDouble.empty();Â
        try {Â
            // try to get value from empty OptionalDouble            Double value = opDouble.orElseThrow();        }        catch (Exception e) {Â
            System.out.println("Exception thrown : "                               + e);        }    }} |
Output:
Exception thrown : java.util.NoSuchElementException: No value present
References: https://docs.oracle.com/javase/10/docs/api/java/util/OptionalDouble.html#orElseThrow()
