OptionalDouble help us to create an object which may or may not contain a double value. The getAsDouble() method returns value If a value is present in OptionalDouble object, otherwise throws NoSuchElementException.
Syntax:
public double getAsDouble()
Parameters: This method accepts nothing.
Return value: This method returns the value described by this OptionalDouble.
Exception: This method throws NoSuchElementException if no value is present
Below programs illustrate getAsDouble() method:
Program 1:
// Java program to demonstrate // OptionalDouble.getAsDouble() method   import java.util.OptionalDouble;   public class GFG {       public static void main(String[] args)     {           // Create an OptionalDouble instance         OptionalDouble opDouble             = OptionalDouble.of( 44356.455 );           System.out.println( "OptionalDouble: "                            + opDouble.toString());           // Get value in this instance         // using getAsDouble()         System.out.println( "Value in OptionalDouble = "                            + opDouble.getAsDouble());     } } |
OptionalDouble: OptionalDouble[44356.455] Value in OptionalDouble = 44356.455
Program 2:
// Java program to demonstrate // OptionalDouble.getAsDouble() method   import java.util.OptionalDouble;   public class GFG {       public static void main(String[] args)     {           try {               // Create an OptionalDouble instance             OptionalDouble opDouble = OptionalDouble.empty();               System.out.println( "OptionalDouble: "                                + opDouble.toString());               // Get value in this instance             // using getAsDouble()             System.out.println( "Value in OptionalDouble = "                                + opDouble.getAsDouble());         }         catch (Exception e) {               System.out.println( "Exception: " + e);         }     } } |
OptionalDouble: OptionalDouble.empty Exception: java.util.NoSuchElementException: No value present
References: https://docs.oracle.com/javase/10/docs/api/java/util/OptionalDouble.html#getAsDouble()