LongToDoubleFunction Interface in Java with Examples

The LongToDoubleFunction 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 long-valued argument and gives a double-valued result.

The lambda expression assigned to an object of LongToDoubleFunction type is used to define its applyAsDouble() which eventually applies the given operation on its only argument. It is similar to using an object of type Function<Long, Double>.

The LongToDoubleFunction interface has only one function:

applyAsDouble()

This method accepts a long-valued argument and gives a double-valued result.

Syntax:

double applyAsDouble(long value)

Parameters: This method takes in one parameter value which is the long-valued argument.

Returns: This method returns a double-valued result.

Below is the code to illustrate applyAsDouble() method:

Program:

import java.util.function.LongToDoubleFunction;

public class Main {
    public static void main(String args[])
    {

        LongToDoubleFunction ob = a -> a / 2;

        // Using applyAsDouble() method
        System.out.println(ob.applyAsDouble(3));
    }
}

Output:

1.0