How often do you encounter SOLID principles in your work?

Daily. They are the foundation for building extendable, maintainable, and testable code.

• Single Responsibility Principle (SRP): Each class or method should do only one thing.
• Open/Closed Principle (OCP): Software entities (classes, modules, functions) should be open for extension but closed for modification.
• Liskov Substitution Principle (LSP): Objects of a base class should be replaceable with objects of derived classes without affecting the correctness of the program.
• Interface Segregation Principle (ISP): Clients should not depend on interfaces they do not use.
• Dependency Inversion Principle (DIP): Higher-level modules should not depend on lower-level modules. Both should depend on abstractions. Abstractions should not depend on details. Details should depend on abstractions.

Applying SOLID helps reduce code coupling, improve readability, and simplify refactoring and testing.

<?php

// Example of SRP: A class for processing orders and a class for sending emails
class OrderProcessor
{
    public function processOrder(array $orderData): bool
    {
        // Order processing logic...
        return true; // Or false in case of failure
    }
}

class Mailer
{
    public function sendOrderConfirmation(string $email, array $orderData): bool
    {
        // Email sending logic...
        return true;
    }
}