Java 8 | IntToLongFunction Interface in Java with Examples Last Updated : 28 Sep, 2018 Comments Improve Suggest changes Like Article Like Report The IntToLongFunction 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 an int-valued argument and gives a long-valued result. The lambda expression assigned to an object of IntToLongFunction type is used to define its applyAsLong() which eventually applies the given operation on its only argument. It is similar to using an object of type Function<Integer, Long> . The IntToLongFunction interface has only one function: applyAsLong() : This method accepts an int-valued argument and gives a long-valued result. Syntax: long applyAsLong(int value) Parameters: This method takes in one parameter value which is the int-valued argument. Returns: This method returns a long-valued result. Below is the code to illustrate applyAsLong() method: Program Java // Java Program to demonstrate // IntToLongFunction's applyAsLong() method import java.util.function.IntToLongFunction; public class Main { public static void main(String args[]) { // Declare the IntToLongFunction IntToLongFunction func = a -> 1000000 * a; // Apply the function to get the result as long // using applyAsLong() System.out.println(func.applyAsLong(2)); } } Output: 2000000 Comment More infoAdvertise with us Next Article Java 8 | IntToLongFunction Interface in Java with Examples P psil123 Follow Improve Article Tags : Java Java - util package java-basics Java 8 Practice Tags : Java Similar Reads Java 8 | IntToDoubleFunction Interface in Java with Examples The IntToDoubleFunction 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 an int-valued argument and gives a double-valued result. The lambda expression assigned to an obj 1 min read IntFunction Interface in Java with Examples The IntFunction 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 an int-valued argument and produces a result of type R. This functional interface takes in only one gener 1 min read ToLongFunction Interface in Java with Examples The ToLongFunction 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 an argument of type T and produces a long-valued result. This functional interface takes in only one g 1 min read ToLongBiFunction Interface in Java with Examples The ToLongBiFunction 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 two arguments of type T and U and produces an long-valued result. This functional interface takes in 2 min read LongFunction Interface in Java with Examples The LongFunction 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 produces a result of type R. This functional interface takes in only one gene 1 min read Like