Java IntConsumer

Introduction

In Java, the IntConsumer interface is a functional interface that represents an operation that accepts a single int-valued argument and returns no result. It is part of the java.util.function package and is commonly used for operations that process int values, such as logging or modifying data.

Table of Contents

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

1. What is IntConsumer?

IntConsumer is a functional interface that performs an operation on a single int input. It is often used in lambda expressions and method references for handling int values.

2. Methods and Syntax

The main methods in the IntConsumer interface are:

• void accept(int value): Performs this operation on the given int argument.
• default IntConsumer andThen(IntConsumer after): Returns a composed IntConsumer that performs this operation followed by the after operation.

Syntax

IntConsumer intConsumer = (int value) -> {
    // operation on value
};

3. Examples of IntConsumer

Example 1: Printing an Integer Value

import java.util.function.IntConsumer;

public class PrintIntExample {
    public static void main(String[] args) {
        // Define an IntConsumer that prints an integer value
        IntConsumer print = (value) -> System.out.println("Value: " + value);

        print.accept(10);
    }
}

Output:

Value: 10

Example 2: Multiplying and Displaying

import java.util.function.IntConsumer;

public class MultiplyExample {
    public static void main(String[] args) {
        // Define an IntConsumer that multiplies an integer by 2 and prints the result
        IntConsumer multiplyAndPrint = (value) -> System.out.println("Multiplied Value: " + (value * 2));

        multiplyAndPrint.accept(5);
    }
}

Output:

Multiplied Value: 10

Example 3: Using andThen

import java.util.function.IntConsumer;

public class AndThenExample {
    public static void main(String[] args) {
        // Define two IntConsumers
        IntConsumer print = (value) -> System.out.println("Value: " + value);
        IntConsumer multiply = (value) -> System.out.println("Multiplied Value: " + (value * 2));

        // Compose the IntConsumers
        IntConsumer combined = print.andThen(multiply);

        combined.accept(7);
    }
}

Output:

Value: 7
Multiplied Value: 14

4. Real-World Use Case: Logging User Actions

In applications, IntConsumer can be used to log user actions represented by integer codes.

import java.util.function.IntConsumer;

public class UserActionLogger {
    public static void main(String[] args) {
        // Define an IntConsumer to log user action codes
        IntConsumer logAction = (actionCode) -> System.out.println("User action logged: " + actionCode);

        logAction.accept(101);
    }
}

Output:

User action logged: 101

Conclusion

The IntConsumer interface is a versatile tool in Java for performing operations on int values without returning a result. It simplifies handling tasks like logging, modifying data, or processing real-time information. Using IntConsumer can lead to cleaner and more efficient code, especially in functional programming contexts. The andThen method allows for easy composition of operations, enhancing code modularity.