PHP Interview: 200 Questions and Answers

The book "PHP Interview: 200 Questions and Answers" is a practical guide for anyone who wants to successfully pass a technical interview for a PHP developer position at any level. Unlike standard textbooks, this book is focused exclusively on questions that are actually asked in interviews at Russian and international IT companies.

The material covers all key topics of modern PHP development:

• PHP Language Basics — data types, operators, control structures, working with arrays and strings, functions, scopes.
• Object-Oriented Programming (OOP) — classes, inheritance, polymorphism, encapsulation, traits, interfaces, abstract classes, design patterns (Singleton, Factory, Repository, and others).
• Working with Databases — SQL, MySQL, PDO, ORM (Eloquent, Doctrine), query optimization, indexes, transactions, table relationships.
• Frameworks and Tools — Laravel, Symfony, Yii2, Composer, Dependency Injection, Middleware, REST API.
• Security — SQL injection, XSS, CSRF, session protection, encryption, data validation.
• Performance and Debugging — caching (Redis, Memcached), profiling (Xdebug), code optimization, working with queues.
• Architecture and Testing — SOLID, DRY, KISS, MVC, Unit testing (PHPUnit), TDD, CI/CD.
• Algorithms and Data Structures — sorting, searching, trees, hash tables, algorithm complexity (Big O).

Each question is accompanied not only by the correct answer but also by an explanation of "why it works this way," which helps to understand the material more deeply and confidently answer the interviewer's follow-up questions.

Who this book is for:

• Junior developers — systematize their knowledge, learn typical questions for their first job.
• Middle developers — fill gaps in theory and prepare for promotion.
• Senior developers — refresh their knowledge of architecture and complex topics.
• Team leads and mentors — can use the book as a checklist for evaluating candidates.

The book is written in simple and clear language, without fluff — just the essence. All code examples are relevant for PHP 8.x and modern frameworks. After reading, you will be ready for any questions — from "what is PSR-4" to "how to design a high-load service on Laravel".

What you will learn:

• How to answer tricky questions about references and object copying.
• How to explain the difference between an interface and an abstract class in 30 seconds.
• How to properly build queries with JOIN and subqueries.
• How to implement class autoloading and why Composer is needed.
• How to protect an application from common vulnerabilities.
• How to pass technical sections with code on a whiteboard.