Here are the Top 10 PHP Interview Questions and Answers (with brief answers) to help candidates prepare effectively:

1. What is PHP and what are its key features?

Answer:
PHP (Hypertext Preprocessor) is a server-side scripting language primarily used for web development.
Key Features:

• Open-source
• Embedded in HTML
• Supports databases (MySQL, PostgreSQL)
• Platform-independent
• Supports OOP (Object-Oriented Programming)

2. What are the differences between echo, print, and print_r()?

Answer:

• echo – Can take multiple parameters, faster, no return value.
• print – Takes one argument, returns 1 (can be used in expressions).
• print_r() – Used to display structured information (mainly arrays and objects).

Top 10 PHP Interview Questions and Answers

3. How does PHP handle variable scope?

Answer: PHP supports:

• Local – Declared inside a function.
• Global – Declared outside functions, accessed using global keyword or $GLOBALS.
• Static – Maintains value between function calls using static keyword.

4. What is the difference between == and === in PHP?

Answer:

• == – Checks value equality after type conversion.
• === – Checks value and type equality.

5. What are sessions and cookies in PHP?

Answer:

• Cookies – Stored on the client-side (browser).
• Sessions – Stored on the server, more secure, identified by a session ID.

Top 10 PHP Interview Questions and Answers

6. How to connect to a MySQL database using PHP?

Answer:

$conn = new mysqli("localhost", "username", "password", "database");
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

7. What is the difference between include, require, include_once, and require_once?

Answer:

• include – Emits a warning on failure, continues execution.
• require – Emits a fatal error on failure, stops execution.
• *_once – Prevents including the same file multiple times.

Top 10 PHP Interview Questions and Answers

8. What are PHP Superglobals?

Answer: Predefined variables accessible globally:

• $_GET, $_POST, $_REQUEST, $_SESSION, $_COOKIE, $_SERVER, $_FILES, $_ENV, $GLOBALS

9. What is the use of isset() and empty() functions?

Answer:

• isset() – Returns true if a variable is set and not null.
• empty() – Returns true if a variable is empty (e.g., 0, '', false, null, etc.)

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

Answer:

• GET – Appends data to URL, less secure, limited size.
• POST – Sends data in request body, more secure, supports larger data.

Let me know if you want an advanced-level set too!

Top 10 PHP Interview Questions and Answers

Top 10 PHP Interview Questions and Answers

Top 10 PHP Interview Questions and Answers