7 Advanced PHP Questions to Ace your Interview (+ Example Code)

You already know and covered the fundamentals of PHP interview questions. You took the time to further understand some more advanced topics about PHP to ace your interview. Yet, as a senior developer, you feel like you need to practice more advanced stuff to truly shine in your tech interview. Well, if that’s really you, then you’ve come to the right place.

There are a lot of things a senior PHP developer should know, so it’s next to impossible to provide you with all the questions you might face. That’s why we’ve gathered some of the key ones, the ones that we feel give you that extra edge to secure that job. Hopefully, you’ll find them useful, too. 

1. Getting ready for advanced PHP concepts and questions

What if you’re one of those PHP developers that want to conquer the web dev world and be the Top G of PHP? How do you then prepare for the senior, hardcore interview questions? 

Don’t worry! In the next chapters, I’ll get you ready for the most advanced PHP interview questions and turn you into the PHP Man of Steel. 

Q1: How would you describe PHP sessions and cookies? 

There are two methods of storing data across multiple pages in PHP, you need to remember: 

• Sessions 
• Cookies (yes, you know those pesky things)

Now, you might be thinking, “Isn’t that the same thing?” Actually, they’re both pretty different, and that’s the No.1 mistake beginner PHP developers make!

Cookies store data on the client’s browser and send it back to the server with each request. On the other hand, sessions store data directly on the server itself. Each session is uniquely identified by a session ID which is stored on the client side as a cookie.

Here comes the important part: Choosing between cookies and sessions depends on what kind of data you’re handling. If it’s something small or non-sensitive, then cookies are fine. 

But if you’re dealing with larger amounts of data or stuff that needs to be kept more secure (like bank details), go for sessions all the way!

Q2: How would you handle exceptions in PHP? 

Think of an exception as a warning light that pops up when something goes south. When you use try/catch blocks in PHP, you’re setting up a system to “catch” these exceptions before they disrupt your code’s normal flow of execution.

And the best part? 

Using these try/catch blocks you have complete control over any issues that arise. It’s like having an emergency kit ready for chaos.

Here’s the catch (pun intended): If you don’t have an appropriate catch block set up for the specific type of error being thrown, your script will come to a grinding halt with a fatal error. So, be sure to set those catch blocks up correctly!

Here’s an example of “catching” the right way:

try {

    throw new Exception(“An error occurred”);

} catch (Exception $e) {

    echo $e->getMessage(); // prints “An error occurred”

}

Q3: How would you describe PHP Object-Oriented Programming (OOP) concepts?

By using OOP, you get super-modular code that’s really easy to maintain and update. 

You’ve got all these different concepts like Class, Object, Property, Method, Constructor, Inheritance, and Interfaces working together to create code that truly rocks.

And let me tell you something else cool — each object can have its own unique properties and methods. It’s like giving each piece of the puzzle its own characteristics while still letting it fit seamlessly into the bigger picture!

For example: Let’s say you have this Class with all sorts of fancy functions and variables. You can create Objects based on this Class with individual functions and data inside them. That way you don’t have to keep rewriting the same old stuff over and over again — genius, right!

2. Bootstrapping your PHP Frameworks knowledge with these interview answers

Now, the fun stuff!

Q1: How would you describe Laravel and CodeIgniter?

Laravel (oh, how senior PHP devs adore this beauty!) is known for its elegant syntax and feature-packed options for modern web development. From ORM (Eloquent) to routing, authentication to caching, and even its Blade templating engine — Laravel has it all.

But the best part?

Laravel has a myriad of helpful tools like their Forge management system for servers and Nova administration panels that make developer’s life a happy place.

In the other corner, CodeIgniter is a lighter framework that’s considered to be pretty user-friendly. It offers fantastic performance while requiring less configuration than some of its heavyweight competitors like (you guessed it) Laravel. 

This framework is perfect for PHP developers who want something smaller and leaner but don’t want to compromise on quality.

Q4: What are other popular PHP frameworks you know of?

Everyone knows about Laravel and CodeIgniter, but you also need to take the following into account:

• Symfony — A highly modular and feature-rich framework used by many high-profile websites.
• Yii — known for its performance and its suitability for large-scale projects.
• Phalcon — Stands out as it’s implemented as a C extension, offering high performance.
• Zend Framework — Now Laminas Project, is another powerful and flexible framework with a strong focus on PHP enterprise development.
• CakePHP — praised for its simplicity and rapid development capabilities.

3. Climbing the ladder of success: PHP best practices every developer must know

The last and the most soul-grinding part of the interview — PHP best practices. Here, it isn’t about technicalities, but the ethics and your way of producing the best code quality you can pull out. 

In this part, techy interviewers test your PHP quality ethics with questions such as:

Q1: What would be your PHP best practices for coding?

These are the key points you MUST cover when answering:

1. Consistent naming conventions — Consistent naming of variables, functions, and classes makes your code more readable and easier to understand.
2. Code comments — Properly commenting on your code helps others understand the purpose of different sections of your code. These are senior PHP devs’ bread and butter!
3. Error reporting — Enabling error reporting during development can help catch issues early.
4. Code reusability — Write reusable code and functions to avoid duplication, reduce errors, and make maintaining your code easier.
5. Avoid using short tags — Short tags aren’t supported on every server, so it’s best to use full PHP tags. Remember, this ain’t HTML we’re talking about.
6. Use OOP — Object-Oriented Programming is a fundamental principle that helps in writing scalable, manageable, and organized code.
7. Secure database queries — Protect your application from SQL injections by using prepared statements or parameter binding.

Q2: How would you go about effectively debugging your PHP code?

Everyone can write PHP code, but the real craft of being a PHP developer lies in debugging! That’s where you’ll spend 70% of your development time and how you’ll advance in the industry.

Here’s what HR will pay close attention to:

1. Understanding the problem — Before you start debugging, you need to understand the problem. What is the expected behavior and how is the actual behavior deviating from it?
2. Reproduce the issue — Try to reproduce the problem consistently. This makes it easier to tell if you’ve successfully fixed the issue.
3. Use error reporting — PHP’s error reporting can point you to the line of code causing an error. Make sure it is turned on during development.
4. Use var_dump() and die() — These can help you see what’s going on in your code. var_dump() displays detailed information about a variable, and die() halts the execution of the script.
5. Use a debugging tool — Xdebug is a powerful debugging tool for every PHP developer. It provides stack traces, function traces in error messages, and a full-featured debugger.
6. Go through the documentation — If you’re getting unexpected results from a PHP function, double-check the documentation. The function may not work the way you think it does.

Getting ready for a PHP interview: Final words of wisdom

So there you have it — A comprehensive PHP interview article series that turns any aspiring PHP developer into a knowledgeable professional. 

Oh and one last tip before you go through that door: A PHP interview isn’t just about answering questions like a computer with 1s and 0s. It’s about demonstrating your understanding, your thinking process, and your communication skills. 

So, make sure besides demonstrating your technical skills, you showcase what a real PHP developer is made of!