The hashCode() method help us to get the hash code of the value, if Double value is present, otherwise 0 (zero) if no Double value is present in OptionalDouble object. Syntax:
public int hashCode()
Parameters: This method does not accepts any parameter. Return value: This method returns hash code value of the present value or 0 if no value is present. Below programs illustrate hashCode() method: Program 1:Â
Java
// Java program to demonstrate// OptionalDouble.hashCode() methodÂ
import java.util.OptionalDouble;Â
public class GFG {Â
    public static void main(String[] args)    {Â
        // create a OptionalDouble instance        OptionalDouble opDouble            = OptionalDouble.of(253255.432525);Â
        System.out.println("OptionalDouble: "                           + opDouble.toString());Â
        // get hashCode value using hashCode()        System.out.println("HashCode value: "                           + opDouble.hashCode());    }} |
Output:
OptionalDouble: OptionalDouble[253255.432525] HashCode value: 885080309
Program 2:Â
Java
// Java program to demonstrate// OptionalDouble.hashCode() methodÂ
import java.util.OptionalDouble;Â
public class GFG {Â
    public static void main(String[] args)    {Â
        // create a OptionalDouble instance        OptionalDouble opDouble            = OptionalDouble.empty();Â
        System.out.println("OptionalDouble: "                           + opDouble.toString());Â
        // get hashCode value using hashCode()        System.out.println("HashCode value: "                           + opDouble.hashCode());    }} |
Output:
OptionalDouble: OptionalDouble.empty HashCode value: 0
References: https://docs.oracle.com/javase/10/docs/api/java/util/OptionalDouble.html#hashCode()
