The stream() method help us to get double value contain by OptionalDouble as DoubleStream.If a value is present, method returns a sequential DoubleStream containing only that value, otherwise returns an empty DoubleStream.
Syntax:
public DoubleStream stream()
Parameters: This method accepts nothing.
Return value: This method returns the optional value as an DoubleStream.
Below programs illustrate stream() method:
Program 1:
// Java program to demonstrate// OptionalDouble.stream() method  import java.util.OptionalDouble;import java.util.stream.DoubleStream;  public class GFG {      public static void main(String[] args)    {          // create a OptionalDouble        OptionalDouble opDouble            = OptionalDouble.of(.3203);          // get value as stream        DoubleStream out = opDouble.stream();          // print value        System.out.print("Value: ");        out.forEach(System.out::print);    }} |
Output:
Program 2:
// Java program to demonstrate// OptionalDouble.stream() method  import java.util.OptionalDouble;import java.util.stream.DoubleStream;  public class GFG {      public static void main(String[] args)    {          // create a empty OptionalDouble        OptionalDouble opDouble            = OptionalDouble.empty();          // get value as stream        DoubleStream out = opDouble.stream();          // print value        System.out.print("length of Double Stream: "                         + out.count());    }} |
Output:
References: https://docs.oracle.com/javase/10/docs/api/java/util/OptionalDouble.html#empty()
