Top PHP Interview Questions

11/22/2025
All Articles

diagram of php interview questions for experienced

Top PHP Interview Questions

Top PHP Interview Questions (2025 Guide)

1. What is PHP?

PHP (Hypertext Preprocessor) is a server-side scripting language used for web development, capable of generating dynamic page content.

2. What are the main features of PHP?

  • Open-source

  • Platform-independent

  • Easy to learn

  • Supports OOP

  • Large community support

  • Integrates with databases like MySQL, PostgreSQL, etc.

3. What is the difference between echo and print?

  • echo: No return value, faster, can take multiple parameters.

  • print: Returns 1, slower, single parameter.

4. What is the difference between GET and POST methods?

  • GET: Data visible in URL, limited length.

  • POST: Data sent in body, more secure, no size limit.

5. What is a session in PHP?

A session stores user information for multiple page requests using a unique session ID.

6. How to start a session in PHP?

session_start();

7. What is a cookie in PHP?

A cookie is a small piece of data stored on the client's browser.

8. What is the difference between session and cookie?

  • Session: Stored on server, secure, temporary.

  • Cookie: Stored on client, less secure, can persist.

9. What is OOP in PHP?

Object-oriented programming includes classes, objects, inheritance, polymorphism, encapsulation, abstraction.

10. What is Composer in PHP?

A dependency manager for PHP that handles libraries and packages.

11. What is PDO in PHP?

PHP Data Objects — a database abstraction layer supporting multiple databases with prepared statements.

12. What are prepared statements?

SQL statements that prevent SQL injection by separating data from SQL queries.

13. What is MVC in PHP frameworks?

Model–View–Controller architecture separating data, UI, and logic.

14. What are traits in PHP?

A mechanism for code reuse in single inheritance languages.

15. What is namespace in PHP?

Namespaces prevent class name conflicts in large applications.

16. What is the difference between include and require?

  • include: Shows warning on failure.

  • require: Stops script execution on failure.

17. What are magic methods in PHP?

Special methods starting with __ like __construct(), __destruct(), __toString().

18. What is autoloading in PHP?

Automatically loads classes when needed using spl_autoload_register().

19. What is error reporting in PHP?

Used to show or hide errors.

error_reporting(E_ALL);
ini_set('display_errors', 1);

20. What are PHP design patterns?

Common patterns include Singleton, Factory, Strategy, Observer, MVC.

 

Article