Top 50+ PHP Interview Questions and Answers

683

PHP interview questions are more focused on practical knowledge than memorized definitions. Interviewers want to see how you think, how you code, and how well you understand the core of PHP. 

This list of 50+ questions is built around real interview patterns—covering syntax, error handling, OOP, forms, sessions, and more. Each answer is written simply, without textbook jargon, so you can revise faster. 

If you have got a PHP interview coming up, start here. You will find solid questions that actually reflect what companies ask.

Fun Fact – W3Techs’ Web Technology Surveys show that PHP powers 74.5% of all websites with a known server-side language.

Note – We have categorized the top PHP interview questions into basics, core, fresher-level, experienced-level, advanced, technical, coding, and company-specific sections for easier revision.

PHP Basic Interview Questions

Here is a list of basic PHP questions asked in interviews along with answers. 

1. What is the difference between echo and print in PHP?

Both echo and print are used to output data. echo can take multiple parameters and does not return a value. print takes only one argument and returns 1, so it can be used in expressions. echo is slightly faster because it doesn’t return anything.

2. How do you declare a variable in PHP?

Variables in PHP start with a dollar sign ($). For example: $name = “John”;. Variable names are case-sensitive and must start with a letter or underscore.

3. What are the different data types supported in PHP?

PHP supports these primary data types:

• String
• Integer
• Float (double)
• Boolean
• Array
• Object
• NULL
• Resource (like file handles or database connections)

4. How does PHP handle type conversions automatically?

PHP uses dynamic typing. It converts data types automatically based on context. For example, adding a string and an integer may result in type juggling where PHP attempts to convert the string to a number.

5. What is the use of isset() in PHP?

isset() checks if a variable is set and is not NULL. It returns true if the variable exists and is not NULL; otherwise, it returns false.

Core PHP Interview Questions

Here are some core PHP interview questions with answers to help you prepare. 

6. What is the difference between include and require?

Both are used to include files in PHP. include shows a warning if the file is not found and continues execution. require throws a fatal error and stops the script if the file is missing.

7. How does PHP handle sessions and cookies?

Sessions store data on the server; cookies store data in the user’s browser. Sessions use a unique session ID and are more secure for sensitive data. Cookies can persist longer but are visible to users.

8. What are magic methods in PHP?

Magic methods are special functions like __construct(), __destruct(), __get(), __set(), and __toString(). They begin with double underscores and allow you to control how objects behave in certain situations, like being converted to a string or having inaccessible properties accessed.

9. Explain the use of error_reporting() in PHP.

error_reporting() controls which errors are reported. For example, error_reporting(E_ALL) will show all types of errors. It’s useful for debugging during development but should be limited in production.

10. How does PHP handle file uploads?

PHP handles file uploads using the $_FILES superglobal. The form must use enctype=”multipart/form-data”. Files are uploaded to a temporary location, and you use move_uploaded_file() to save them to a desired directory.

PHP Interview Questions for Freshers

These are some commonly asked PHP interview questions and answers for freshers.

11. What is PHP and what is it commonly used for?

PHP is a server-side scripting language designed for web development. It can generate dynamic page content, handle form data, manage sessions, interact with databases, and create entire web applications.

12. How do you create a simple function in PHP?

Use the function keyword followed by the function name and parentheses.
Example:

function greet($name) {

    return “Hello, ” . $name;

}

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

== checks for value equality after type juggling. === checks for both value and type. For example, 5 == “5” is true, but 5 === “5” is false.

14. What are superglobals in PHP?

Superglobals are built-in variables available in all scopes. Examples include $_POST, $_GET, $_SESSION, $_FILES, $_COOKIE, $_SERVER, and $_REQUEST.

15. How do you retrieve data from a submitted HTML form in PHP?

If the form uses POST, use $_POST[‘input_name’]. If it uses GET, use $_GET[‘input_name’]. Always validate and sanitize inputs before using them.

PHP Interview Questions for Experienced

Let’s go through the important PHP experienced interview questions and answers. 

16. What design patterns have you used in your PHP projects?

Common ones include Singleton for shared instances, Factory for object creation, MVC (Model-View-Controller) for structuring applications, and Dependency Injection for managing class dependencies.

17. How do you manage large-scale PHP applications?

“I organize code using clear folder structures, separate logic into reusable classes or services, use namespaces, and follow SOLID principles. Tools like Composer help manage dependencies, and frameworks like Laravel offer structure.”

18. What tools do you use for debugging PHP code?

“I use var_dump() and print_r() for quick checks, but Xdebug with an IDE like PHPStorm or VS Code is best for step-through debugging. Logging tools like Monolog are useful in production.”

19. How do you handle database migrations in PHP projects?

“I use migration tools provided by frameworks, like Laravel’s Artisan. They allow version control of schema changes and make it easier to manage database changes across environments.”

20. What is your approach to writing unit tests in PHP?

“I use PHPUnit for testing. I structure code to be testable, avoid tight coupling, and mock dependencies where needed. Testing improves reliability and helps prevent regressions during updates.”

Also Read - Top 35+ Laravel Interview Questions and Answers

PHP Interview Questions for 1 Year Experience

These are some frequently asked 1 year experience PHP interview questions. 

• Tell me about a PHP project you worked on recently.
• How do you handle errors or bugs when working on a PHP task?
• What would you do if a user reports a bug that you can’t reproduce?

PHP Interview Questions for 2 Year Experience

Here are some 2 year experience PHP interview questions to help you prepare. 

• How have your responsibilities changed in the last year as a PHP developer?
• Describe a time when you had to meet a tight deadline with a PHP project.
• How would you optimize a slow-performing PHP script?

PHP Interview Questions for 5 Year Experience

If you have 5 years of experience, you might also come across interview questions on PHP for experienced like these. 

• What kind of architecture do you usually follow in PHP projects?
• Tell me about a challenge you faced leading a PHP team or module.
• How would you handle a situation where legacy PHP code is affecting new development?

PHP Interview Questions for 8 Years Experienced

Here are some common PHP questions asked in interview to candidates with 8 years of experience. 

• What has been your biggest PHP project so far and your role in it?
• Describe a time when your technical decision significantly improved the project.
• How would you guide a junior developer stuck on a tricky PHP bug?

PHP Interview Questions for 10 Years Experienced

• How do you stay updated with changes in PHP over the years?
• Share an experience where you had to convince stakeholders to refactor old PHP code.
• How do you plan and architect a PHP project from scratch?

Note – Most PHP experience interview questions aren’t about tricky syntax, but about how you solve real problems and structure clean, efficient code.

PHP Advanced Interview Questions

These are some advanced PHP interview questions and answers for your preparation. 

21. What are traits in PHP and when would you use them?

Traits let you reuse code in multiple classes without using inheritance. They’re useful when you want to share methods across unrelated classes. You use the use keyword inside a class to include a trait.

22. Explain how late static binding works in PHP.

Late static binding allows PHP to reference the class that was actually called at runtime, not the one where the method is defined. It uses the static:: keyword instead of self::.

23. How do anonymous classes work in PHP?

Anonymous classes are declared using new classes and are useful for simple, one-time-use objects, especially in closures or when mocking for tests.

PHP Technical Interview Questions

Here are some frequently asked PHP questions asked in interviews during technical rounds. 

24. What is autoloading in PHP and how does it work?

Autoloading loads classes automatically when they are used, without a manual include. PHP uses spl_autoload_register() or PSR-4 autoloading via Composer to manage this efficiently.

25. What happens if you send headers after output in PHP?

PHP throws a warning and fails to set headers. Headers must be sent before any actual output. Use output buffering if needed to avoid this issue.

26. How would you handle large file uploads in PHP?

“I’d adjust upload_max_filesize and post_max_size in php.ini, use move_uploaded_file() safely, and validate file size and type on both client and server.”

Note – Technical PHP interview question answer sets often include topics like error handling, OOP concepts, database interactions, session management, and more.

PHP Developer Interview Questions

Here are some PHP interview questions and answers for developers. 

27. How do you manage routes in a PHP application?

“In plain PHP, I use condition-based routing. In frameworks like Laravel, I define routes in files like web.php, which maps URLs to controllers or closures.”

28. What steps do you take to write secure PHP code?

“I validate all user input, use prepared statements for database queries, escape output to prevent XSS, and avoid exposing sensitive error messages.”

29. How do you handle version control in your PHP workflow?

“I use Git for version control. I create branches for features or bugs, write clear commit messages, and regularly push to a shared repository like GitHub.”

Logical Interview Questions in PHP

These are some logical PHP questions asked in interviews. 

30. Write a PHP function to check if a number is prime.

function isPrime($num) {

  if ($num < 2) return false;

  for ($i = 2; $i <= sqrt($num); $i++) {

    if ($num % $i === 0) return false;

  }

  return true;

}

31. How would you remove duplicates from an array without using built-in functions?

Loop through the array, store seen values in another array, and skip if already stored.

32. Write a script to sort an array without using sort functions.

Use bubble sort or selection sort manually by comparing and swapping elements in nested loops.

Other Important PHP Interview Questions

PHP Array Interview Questions

Here are some important Array interview questions in PHP. 

• What’s the difference between array_merge and array_combine?
• How do you sort an associative array by values?
• How do you check if a key exists in an array?

PHP and MySQL Interview Questions

• How do you prevent SQL injection in PHP while using MySQL?
• What’s the difference between mysqli and PDO?
• How do you execute a prepared statement using PDO?

PHP Drupal Interview Questions

• What is a hook in Drupal?
• How do you create a custom module in Drupal?
• How is user access control handled in Drupal using PHP?

Also Read - Top 30+ PL/SQL Interview Questions and Answers

PHP Program Questions

These questions on PHP programming are commonly asked to check your practical coding skills and how you approach real-world problems. 

33. Write a PHP program to reverse a string.

function reverseString($str) {

  $rev = ”;

  for ($i = strlen($str) – 1; $i >= 0; $i–) {

    $rev .= $str[$i];

  }

  return $rev;

}

34. Write a PHP program to check if a number is even or odd.

function isEven($num) {

  return $num % 2 === 0 ? “Even” : “Odd”;

}

35. Write a PHP program to calculate factorial of a number.

function factorial($n) {

  $fact = 1;

  for ($i = 2; $i <= $n; $i++) {

    $fact *= $i;

  }

  return $fact;

}

36. Write a PHP program to print Fibonacci series.

function fibonacci($n) {

  $a = 0; $b = 1;

  echo “$a $b “;

  for ($i = 2; $i < $n; $i++) {

    $c = $a + $b;

    echo “$c “;

    $a = $b;

    $b = $c;

  }

}

PHP Coding Interview Questions

Now, let’s cover some coding-related PHP interview questions and answers. 

37. Write a function to find the largest element in an array.

function findLargest($arr) {

  $max = $arr[0];

  foreach ($arr as $num) {

    if ($num > $max) {

      $max = $num;

    }

  }

  return $max;

}

38. Write a function to count the number of vowels in a string.

function countVowels($str) {

  $count = 0;

  $vowels = [‘a’,’e’,’i’,’o’,’u’,’A’,’E’,’I’,’O’,’U’];

  for ($i = 0; $i < strlen($str); $i++) {

    if (in_array($str[$i], $vowels)) {

      $count++;

    }

  }

  return $count;

}

39. Write a PHP function to check if a string is a palindrome.

function isPalindrome($str) {

  $str = strtolower(preg_replace(‘/[^a-z0-9]/’, ”, $str));

  return $str === strrev($str);

}

40. Write a PHP function to calculate the sum of digits in a number.

function sumOfDigits($num) {

  $sum = 0;

  while ($num > 0) {

    $sum += $num % 10;

    $num = (int)($num / 10);

  }

  return $sum;

}

PHP Viva Questions

Here are some commonly asked PHP viva questions and answers. 

41. What does PHP stand for?

PHP originally meant Personal Home Page, now it stands for PHP: Hypertext Preprocessor.

42. What is the difference between GET and POST?

GET sends data via URL; POST sends it in the request body. POST is more secure for forms.

43. Can you explain how PHP handles sessions?

PHP stores session data on the server and uses a session ID via cookies to link the user to their data.

44. What are the rules for naming variables in PHP?

Must start with $, followed by a letter or underscore. No spaces or special characters.

45. What is the use of the explode() function?

explode() splits a string into an array using a delimiter.

Company-Specific PHP Interview Questions

TCS PHP Interview Questions

1. How do you debug a PHP application?
2. What is your approach to handling form validation in PHP?
3. How do you manage configuration in a PHP project?

WordPress PHP Interview Questions

1. How do you create a custom post type in WordPress?
2. What are action and filter hooks in WordPress?
3. How do you enqueue scripts and styles in a WordPress theme?

Chetu Interview Questions for PHP

1. How do you handle API integration in PHP?
2. What is your approach to working with third-party libraries in PHP?
3. How do you handle user authentication in PHP?

Cognizant PHP Interview Questions

1. What is MVC and how have you used it in PHP?
2. How do you handle file uploads securely in PHP?
3. How would you migrate a PHP application to a new server?

Infosys PHP Interview Questions

1. How do you manage session timeout in PHP?
2. What is the difference between == and === in PHP?
3. Explain how you would write a login system in PHP.

Accenture PHP Interview Questions

1. What are namespaces and how do you use them in PHP?
2. How do you deal with database errors in PHP?
3. How do you handle file permissions in PHP projects?
4. Can you explain object-oriented programming concepts?

Also Read - Top 50+ OOPs Interview Questions and Answers for 2025

Capgemini PHP Interview Questions

1. What is the full form of PHP?
2. How do you use CURL in PHP?
3. What are some common security mistakes in PHP development?
4. Explain the use of Composer in PHP.

FirstCry Interview Questions for PHP Developer

1. How do you handle image uploads and storage in PHP?
2. What caching techniques have you used with PHP?
3. How do you write reusable functions in PHP?
4. What do you do when your schedule is interrupted?

Nagarro PHP Interview Questions

1. What’s your approach to optimizing PHP performance?
2. How do you structure code in a large PHP project?
3. How would you refactor legacy PHP code?

Tech Mahindra PHP Interview Questions

1. How do you manage environment variables in PHP?
2. Can you explain the basic concepts of PHP?
3. What steps do you take to secure PHP APIs?
4. How do you handle background jobs or scheduled tasks in PHP?

Wrapping Up

These top 50+ PHP interview questions and answers cover what you really need to know—basic syntax, real-world coding, and advanced concepts. Use them to revise smart and walk into your interview with confidence.

Looking for PHP jobs? Check out Hirist—an online job portal built for tech professionals. Find the best PHP roles across India, all in one place.

FAQs

What is the best way to prepare for a PHP interview?

Start by revising core concepts. Then practice coding problems. Finally, review real interview questions like the ones listed in this blog.

Do PHP interviews include coding tests?

Yes, especially for developer roles. You may be asked to write functions, debug code, or build small programs during the interview.

What skills should a PHP developer have?

You should know core PHP, OOP, MySQL, basic security, and version control. Some roles also need knowledge of frameworks like Laravel.

Are frameworks like Laravel commonly asked about in interviews?

Yes. Many companies use Laravel or similar frameworks. Expect questions on routing, controllers, models, and migrations if the role requires it.

What are the most-asked PHP interview questions?

Common ones include differences between echo and print, include vs require, handling sessions, and writing basic PHP programs or functions.

What is the average salary of a PHP developer in India?

According to AmbitionBox, PHP developer salaries in India range from ₹1.1 Lakh to ₹6.8 Lakhs per year for those with 1 to 6 years of experience.

Where can I find more PHP interview questions?

You can explore developer forums, GitHub repos, and blogs like this one. Also, check Hirist for job listings with role-specific requirements.

What does escaping to PHP mean?

Escaping to PHP means switching from HTML to PHP code using <?php … ?> tags. It tells the server to process the code inside as PHP.

What are some commonly asked Symfony interview questions?

Here are a few commonly asked questions during Symfony interviews –

• What is Symfony, and how does it differ from other PHP frameworks?
• What are Bundles in Symfony?
• How does routing work in Symfony?
• What is the purpose of the service container?
• How do you create and use forms in Symfony?
• What is Doctrine, and how is it used with Symfony?
• How do you implement event listeners or subscribers in Symfony?