The DoubleFunction Interface is a part of the java.util.function package which has been introduced since Java 8, to implement functional programming in Java. It represents a function which takes in a double-valued argument and produces a result of type R.
This functional interface takes in only one generic, namely:-
- R: denotes the type of the output of this function
The lambda expression assigned to an object of DoubleFunction type is used to define its apply() which eventually applies the given operation on its only argument. It is similar to using an object of type Function<Double, R>.
The DoubleFunction interface has only one function:
This method accepts a double-valued argument and gives a result of type R.
R apply(double value)
Parameters: This method takes in one parameter value which is a double-valued argument.
Returns: This method returns a value of type R.
Below is the code to illustrate apply() method:
- DoubleStream flatMap(DoubleFunction mapper) in Java
- Java.util.function.DoublePredicate interface in Java with Examples
- Java.util.function.BiPredicate interface in Java with Examples
- Java.util.function.IntPredicate interface in Java with Examples
- Java.util.function.LongPredicate interface in Java with Examples
- SortedMap Interface in Java with Examples
- Supplier Interface in Java with Examples
- DoubleConsumer Interface in Java with Examples
- IntConsumer Interface in Java with Examples
- LongToDoubleFunction Interface in Java with Examples
- LongConsumer Interface in Java with Examples
- ToLongBiFunction Interface in Java with Examples
- Java 8 | LongSupplier Interface with Examples
- LongToIntFunction Interface in Java with Examples
- Java 8 | BooleanSupplier Interface with Examples
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to firstname.lastname@example.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.