Java ObjDoubleConsumer

Introduction

In Java, the ObjDoubleConsumer interface is a functional interface that represents an operation that accepts an object and a double-valued argument and returns no result. It is part of the java.util.function package and is commonly used for operations that involve both an object and a double value, such as modifying an object’s state.

Table of Contents

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

1. What is ObjDoubleConsumer?

ObjDoubleConsumer is a functional interface that performs an operation on an object and a double value without returning any result. It is useful for scenarios where an object’s state needs to be modified based on a double input.

2. Methods and Syntax

The main method in the ObjDoubleConsumer interface is:

• void accept(T t, double value): Performs this operation on the given object and double argument.

Syntax

ObjDoubleConsumer<T> objDoubleConsumer = (T t, double value) -> { // operation on t and value }; 

3. Examples of ObjDoubleConsumer

Example 1: Updating Account Balance

import java.util.function.ObjDoubleConsumer; class Account { private String name; private double balance; public Account(String name, double balance) { this.name = name; this.balance = balance; } public void deposit(double amount) { this.balance += amount; } @Override public String toString() { return name + "'s balance: " + balance; } } public class AccountUpdateExample { public static void main(String[] args) { Account account = new Account("John", 100.0); // Define an ObjDoubleConsumer that deposits a double value to an account ObjDoubleConsumer<Account> deposit = (acc, amount) -> acc.deposit(amount); deposit.accept(account, 50.0); System.out.println(account); } } 

Output:

John's balance: 150.0 

Example 2: Applying a Discount to a Product

import java.util.function.ObjDoubleConsumer; class Product { private String name; private double price; public Product(String name, double price) { this.name = name; this.price = price; } public void applyDiscount(double discount) { this.price -= this.price * discount / 100; } @Override public String toString() { return name + "'s price after discount: " + price; } } public class ProductDiscountExample { public static void main(String[] args) { Product product = new Product("Laptop", 1000.0); // Define an ObjDoubleConsumer that applies a discount to a product ObjDoubleConsumer<Product> applyDiscount = (prod, discount) -> prod.applyDiscount(discount); applyDiscount.accept(product, 10.0); System.out.println(product); } } 

Output:

Laptop's price after discount: 900.0 

4. Real-World Use Case: Logging Temperature Readings

In applications, ObjDoubleConsumer can be used to log temperature readings to a sensor object.

import java.util.function.ObjDoubleConsumer; class Sensor { private String id; public Sensor(String id) { this.id = id; } public void logTemperature(double temperature) { System.out.println("Sensor " + id + " recorded temperature: " + temperature); } } public class TemperatureLoggingExample { public static void main(String[] args) { Sensor sensor = new Sensor("A1"); // Define an ObjDoubleConsumer to log temperature readings ObjDoubleConsumer<Sensor> logTemperature = (sens, temp) -> sens.logTemperature(temp); logTemperature.accept(sensor, 25.5); } } 

Output:

Sensor A1 recorded temperature: 25.5 

Conclusion

The ObjDoubleConsumer interface is a versatile tool in Java for performing operations on an object and a double value without returning a result. It simplifies handling tasks like updating object states or logging information. Using ObjDoubleConsumer can lead to cleaner and more efficient code, especially in functional programming contexts.