Java 8 | DoubleToIntFunction Interface in Java with Example

The DoubleToIntFunction 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 gives an int-valued result. The lambda expression assigned to an object of DoubleToIntFunction 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<Double, Integer>. The DoubleToIntFunction interface has only one function: applyAsInt() : This method accepts a double-valued argument and gives an int-valued result. Syntax:

int applyAsInt(double value)

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

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

import java.util.function.DoubleToIntFunction;

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

        // Create a DoubleToIntFunction
        DoubleToIntFunction truncate = a -> (int)a;

        // Apply the function using applyAsInt()
        System.out.println(truncate.applyAsInt(10.6));
    }
}