If you’re reading this, then you’re probably looking to hire a PHP developer, but the problem is you do not know what to ask.

Testing the practical knowledge of the candidate is imperative and hence not all your questions can be theoretical. Simulation-based PHP technical assessments have become the most reliable way of testing candidate’s PHP programming skills. These tests evaluate the candidate's applied skills gained through real work experience, rather than just theoretical knowledge.

In this article, we will give you a few tips on how to take interviews for hiring PHP developers and also give you a list of the advanced PHP interview questions you can ask.

It is quite obvious that every job has certain needs and requirements that need to be fulfilled. And, it is your to hire the best possible candidate for that job role. When it comes to hiring PHP developers, there are certain things you need to keep an eye out for.

• Any and every PHP developer needs to have an excellent understanding of CSS, HTML, and JAVASCRIPT. HTML is the most important of them all. Possessing knowledge about these three languages is essential for PHP developers.
• The candidate should know how to use SQL for the management of RDBMS (Relational Database Management System) and other purposes as well.
• Evaluate their understanding of frameworks, such as Codelgniter, CakePHP (particularly if you're working on a project that needs PHP4 compatibility), and ATK4 as they are all required to create large-scale applications.
• You should also evaluate their ability to work with other plugins. There are several online code editors that you can use to assess their skill levels. Furthermore, there are many live interview tools available. You can use them to help you choose the best possible candidate.

Now that you know what you are looking for in a PHP developer, here are some questions you can ask. You can even Google the answers and get a better understanding of the subject.

1. Does PHP support variable-length argument functions?
2. Explain soundex() and metaphone().
3. What is the distinction between Zend Framework 2 and Zend Framework 1?
4. By using CURL, how do you transfer data in the header?
5. What are the various tables (Engine) available in MySQL, and which is the default?
6. Compare and contrast MyISAM Static and MyISAM Dynamic.
7. How do I use PHP to extract values from one database server and place them in another?
8. What's the distinction between if ($var == 'value') and if ('value' == $var)?
9. Write a script that will display the following string
   
   "The memory of that scene for me is like a frame of film forever frozen at that moment: the red carpet, the green lawn, the white house, the leaden sky. The new president and his first lady. - Richard M. Nixon"
   
   and the words 'red', 'green', and 'white' will come from $color.
   
10. What is the process for enabling error reporting in PHP?
11. In PHP 5, are objects transferred by value or by reference? Explanation
12. Why will you choose === over ==? Explanation
13. What would each one of the statements below produce, and why
    var_dump('0123' === 123);
    var_dump('0123' == 123);
    var_dump(0123 == 123);
14. In PHP, how do you describe a constant? How would you know if a constant in PHP is defined?
15. What action would you undertake to troubleshoot a website you created whenever I access it and see a vacant white screen?
16. How do you develop classes in OOP to develop a rudimentary Twitter-style status system?
17. Tell us about your web service interactions.
18. Have you worked with a PHP framework before? What systems have you worked in before?
19. Do you have a favorite framework? Justify your answer
20. Differentiate between array_filter, array_map, and an array walk.
21. Write a PHP program to find the single element in an array where every element appears three times except for one.

The first thing you should know is that you can take PHP interviews without being a techie. But at the same time, you should also pay attention to certain details that entail certain job roles.

Getting the help of online hiring tools is also a great idea. 42% of the organizations out there state that investing in online hiring tools enhances their recruitment process.

Online Coding Tests

The concept of online tests is not new, but several new modifications can make life easier for us. If you’re an HR who is taking interviews for PHP developers without possessing any knowledge on the subject, then you should consider using online tools such as online PHP code editors or live coding interview tools. There are online interview sites that you can use for free, but it would be good if you opt for the paid version as it will have more features for you to choose from.

Moreover, according to Finances Online, 87% of HRs and recruiters in the US already use advanced software in one way or another to hire candidates and so should you. These online tools help in assessing the skill level of the candidate, which, in turn, will help you make an informed decision.

These are only a handful of the numerous things you could do to conduct a PHP interview even if you aren't a tech expert. The HR department's responsibility is to choose the right candidate, and not necessarily the most experienced.

That is why you must ensure that you not only focus on the technical aspects of it, but you also pay attention to the other important factors.

All of the aforementioned factors will significantly assist you in recruiting a good PHP developer, but learning a little bit about technology/programming is the most efficient way to hire one. So, be creative and just go for it.