OptionalDouble help us to create an object which may or may not contain a Double value. The isPresent() method help us to get the answer that double value is present in OptionalDouble object or not. If a double value is present, returns true, otherwise false.
Syntax:
public boolean isPresent()
Parameters: This method accepts nothing.
Return value: This method returns true if a value is present, otherwise false
Below programs illustrate isPresent() method:
Program 1:
// Java program to demonstrate// OptionalDouble.isPresent() method  import java.util.OptionalDouble;  public class GFG {      public static void main(String[] args)    {          // create a OptionalDouble        OptionalDouble opDouble            = OptionalDouble.of(3148.1345);          // get value using isPresent()        System.out.println("OptionalDouble"                           + " has a value= "                           + opDouble.isPresent());    }} |
Output:
OptionalDouble has a value= true
Program 2:
// Java program to demonstrate// OptionalDouble.isPresent() method  import java.util.OptionalDouble;  public class GFG {      public static void main(String[] args)    {          // create a OptionalDouble        OptionalDouble opDouble            = OptionalDouble.empty();          // try to get that value is present or not        boolean response = opDouble.isPresent();          if (response)            System.out.println("Value present");        else            System.out.println("Value absent");    }} |
Output:
Value absent
References: https://docs.oracle.com/javase/10/docs/api/java/util/OptionalDouble.html#isPresent()
