LongToIntFunction Interface in Java with Examples

The LongToIntFunction 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 an int-valued result. The lambda expression assigned to an object of DoubleToLongFunction type is used to define its applyAsInt() which eventually applies the given operation on its only argument. It is similar to using an object of type Function<Long, Integer>. The LongToIntFunction interface has only one function:

applyAsInt()

This method accepts a long-valued argument and gives an int-valued result. Syntax:

int applyAsInt(long value)

Parameters: This method takes in one parameter value which is the long-valued argument. Returns: This method returns an int-valued result. Below is the code to illustrate applyAsInt() method: Program Java

// Java Program to demonstrate
// LongToIntFunction's applyAsInt() method

import java.util.function.LongToIntFunction;

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

        // Instantiating LongToIntFunction
        LongToIntFunction ob = a -> (int)a * 100000;

        // Applying the above function
        // using applyAsInt()
        System.out.println(ob.applyAsInt(2));
    }
}