Java IntToLongFunction

Introduction

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

Table of Contents

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

1. What is IntToLongFunction?

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

2. Methods and Syntax

The main method in the IntToLongFunction interface is:

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

Syntax

IntToLongFunction intToLongFunction = (int value) -> {
    // operation on value
    return result;
};

3. Examples of IntToLongFunction

Example 1: Converting Integer to Long

import java.util.function.IntToLongFunction;

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

        long result = intToLong.applyAsLong(5);
        System.out.println("Converted Value: " + result);
    }
}

Output:

Converted Value: 5

Example 2: Multiplying by a Factor

import java.util.function.IntToLongFunction;

public class MultiplyExample {
    public static void main(String[] args) {
        // Define an IntToLongFunction that multiplies an int by a long factor
        IntToLongFunction multiplyByFactor = (value) -> value * 1000L;

        long result = multiplyByFactor.applyAsLong(3);
        System.out.println("Multiplied Value: " + result);
    }
}

Output:

Multiplied Value: 3000

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

In applications, IntToLongFunction can be used to convert time in seconds (as integers) to milliseconds (as long values).

import java.util.function.IntToLongFunction;

public class TimeConverter {
    public static void main(String[] args) {
        // Define an IntToLongFunction to convert seconds to milliseconds
        IntToLongFunction secondsToMillis = (seconds) -> seconds * 1000L;

        long milliseconds = secondsToMillis.applyAsLong(60);
        System.out.println("Milliseconds: " + milliseconds);
    }
}

Output:

Milliseconds: 60000

Conclusion

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