Java LongToIntFunction

Introduction

In Java, the LongToIntFunction interface is a functional interface that represents a function that accepts a long-valued argument and produces an int result. It is part of the java.util.function package and is commonly used for operations that convert or process long values into int values.

Table of Contents

1. What is LongToIntFunction?
2. Methods and Syntax
3. Examples of LongToIntFunction
4. Real-World Use Case
5. Conclusion

1. What is LongToIntFunction?

LongToIntFunction is a functional interface that takes a long as input and returns an int. It is useful for scenarios where long values need to be converted or processed into int values.

2. Methods and Syntax

The main method in the LongToIntFunction interface is:

• int applyAsInt(long value): Applies this function to the given argument and returns an int result.

Syntax

LongToIntFunction longToIntFunction = (long value) -> {
    // operation on value
    return result;
};

3. Examples of LongToIntFunction

Example 1: Converting Long to Int

import java.util.function.LongToIntFunction;

public class LongToIntExample {
    public static void main(String[] args) {
        // Define a LongToIntFunction that converts a long to an int
        LongToIntFunction longToInt = (value) -> (int) value;

        int result = longToInt.applyAsInt(100L);
        System.out.println("Converted Value: " + result);
    }
}

Output:

Converted Value: 100

Example 2: Calculating Remainder

import java.util.function.LongToIntFunction;

public class RemainderExample {
    public static void main(String[] args) {
        // Define a LongToIntFunction that calculates the remainder of a long divided by 10
        LongToIntFunction remainder = (value) -> (int) (value % 10);

        int result = remainder.applyAsInt(123L);
        System.out.println("Remainder: " + result);
    }
}

Output:

Remainder: 3

4. Real-World Use Case: Converting Milliseconds to Seconds

In applications, LongToIntFunction can be used to convert time in milliseconds to seconds.

import java.util.function.LongToIntFunction;

public class MillisecondsToSecondsConverter {
    public static void main(String[] args) {
        // Define a LongToIntFunction to convert milliseconds to seconds
        LongToIntFunction millisToSeconds = (millis) -> (int) (millis / 1000);

        int seconds = millisToSeconds.applyAsInt(10000L);
        System.out.println("Seconds: " + seconds);
    }
}

Output:

Seconds: 10

Conclusion

The LongToIntFunction interface is a practical tool in Java for converting long values to int results. It is particularly beneficial in applications requiring type conversion or mathematical processing. Using LongToIntFunction can lead to cleaner and more efficient code, especially in functional programming contexts.