PHP
PHP Interview Questions and Answers
1. What is PHP?
PHP (Hypertext Preprocessor) is an open-source server-side scripting language used to create dynamic web pages.
2. What are the key features of PHP?
- Open source
- Platform independent
- Supports databases like MySQL
- Easy integration with HTML and JavaScript
3. What are PHP Variables?
Variables in PHP are represented by a $ symbol and are used to store values such as strings, numbers, or arrays.
4. What is a PHP Array?
A PHP array is a data structure that holds multiple values, such as indexed, associative, or multidimensional arrays.
5. What is the difference between Echo and Print in PHP?
- Echo: Faster, can output multiple strings.
- Print: Returns a value, but slower and less versatile.
6. What is PHP used for?
PHP is used for web development, database operations, session management, and interacting with APIs.
7. What is the difference between GET and POST methods in PHP?
- GET: Sends data via URL, limited data size, less secure.
- POST: Sends data in the HTTP body, more secure, larger data size.
8. What is PHP session management?
Sessions in PHP are used to store user data across multiple pages using the $_SESSION superglobal.
9. What is PHP file inclusion?
Include and require are used to insert one PHP file into another for modularity and code reuse.
10. What are PHP data types?
PHP supports data types like string, integer, float, array, boolean, and object.
11. What is the difference between AND in PHP?
- ==: Compares values.
- ===: Compares values and types.
12. What is PDO in PHP?
PHP Data Objects (PDO) is a database access layer that supports multiple databases and ensures prepared statements for security.
13. How does PHP handle errors?
PHP handles errors using functions like error_reporting(), custom error handlers, and logging via log_errors.
14. What is the use of cookie in PHP?
$_COOKIE is a global variable that stores small data files in the user’s browser for session management.
15. What is the difference between Include and Require?
- Include(): Issues a warning if the file is missing.
- Require(): Stops execution if the file is missing.
16. What is Laravel and how does it relate to PHP?
Laravel is a popular PHP framework offering tools for routing, authentication, and database management.
17. What are the benefits of using PHP frameworks?
PHP frameworks like Laravel and CodeIgniter offer faster development, MVC architecture, and better code maintainability.
18. What is Composer in PHP?
Composer is a dependency manager for PHP that handles library installations and updates efficiently.
19. What is the MVC pattern in PHP frameworks?
MVC (Model-View-Controller) separates an application’s data (Model), UI (View), and logic (Controller).
20. How does PHP handle REST APIs?
PHP handles REST APIs by parsing HTTP requests, responding with JSON, and using frameworks like Slim or Laravel.
21. How do you connect PHP to Mysql?
Use mysqli_connect() or PDO to establish secure database connections in PHP.
22. What is a PHP regular expression?
PHP uses preg_match() and related functions to perform pattern matching and text processing.
23. How do you secure PHP applications?
Techniques include input validation, using prepared statements, password hashing, and enabling HTTPS.
24. What is the purpose of the .htaccess file in PHP?
.htaccess configures URL rewriting, security rules, and redirects for PHP web applications.
25. What is the difference between Static and Dynamic websites in PHP?
- Static: Fixed content, no database interaction.
- Dynamic: Real-time content changes, database-driven.
