The ifPresent(java.util.function.DoubleConsumer) method helps us to perform the specified DoubleConsumer action the value of this OptionalDouble object. If a value is not present in this OptionalDouble, then this method does nothing.
Syntax:
public void ifPresent(DoubleConsumer action)
Parameters: This method accepts a parameter action which is the action to be performed on this Optional, if a value is present.
Return value: This method returns nothing.
Exception: This method throw NullPointerException if a value is present and the given action is null.
Below programs illustrate ifPresent(DoubleConsumer) method:
Program 1:
// Java program to demonstrate // OptionalDouble.ifPresent(DoubleConsumer) method import java.util.OptionalDouble;
public class GFG {
public static void main(String[] args)
{
// create a OptionalDouble
OptionalDouble opdouble = OptionalDouble.of( 0.23425 );
// apply ifPresent(DoubleConsumer)
opdouble.ifPresent((value) -> {
value = Math.pow(value, 4 );
System.out.println("Value after modification:=> "
+ value);
});
}
} |
Output:
// Java program to demonstrate // OptionalDouble.ifPresent(DoubleConsumer) method import java.util.OptionalDouble;
public class GFG {
public static void main(String[] args)
{
// create a OptionalDouble
OptionalDouble opdouble = OptionalDouble.empty();
// apply ifPresent(DoubleConsumer)
opdouble.ifPresent((value) -> {
System.out.println("Value:=> "
+ value);
});
System.out.println("As OptionalDouble is empty value"
+ " is not modified");
}
} |
Output: