OOP Intro

Why OOP

Object-Oriented Programming (OOP) helps you organize code around responsibilities. In real applications, OOP reduces duplication, improves testability, and makes your codebase easier to maintain as it grows.

OOP vs “One Big PHP File”

Small scripts can live in one file, but production apps quickly become unmanageable without structure. OOP helps you split logic into layers like controllers, services, repositories, and domain models.

Frameworks Are OOP

Laravel, Symfony, and most modern PHP ecosystems are built around OOP concepts: classes, dependency injection, interfaces, and autoloading. If you understand OOP well, frameworks become much easier.

Core Concepts

OOP is mostly about: encapsulation (hide internal details), composition (build objects from other objects), and clear contracts (interfaces). In this section, we will focus on practical OOP patterns you will use in backend engineering.

Production Tip

Do not do OOP just to “use classes”. Use it to create clear boundaries and predictable code. Keep classes small, focused, and easy to test.