PHP Interview Questions (With Example Answers)

By Indeed Editorial Team

Updated 16 October 2022

Published 6 June 2021

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

PHP is a web-based server scripting language. It is a powerful tool used to generate webpages and apps. The webpages developed with PHP are dynamic and interactive. With the increasing adoption of web-based solutions, PHP has become an essential skill for any role associated with web development. If you appear for a PHP interview, you are required to be prepared to face a lot of technical questions. In this article, we list a few common PHP interview questions along with sample answers and share some tips to help you prepare better for your interview.

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Common PHP Interview Questions With Sample Answers

Here are a few common PHP interview questions the interviewers may ask you, along with sample answers:

1. What is PHP?

The interviewers ask this question to begin the interview and to test your basic understanding of PHP. You do not need a detailed answer to this question. Be direct in your response, briefly define what PHP is and add a couple of applications to cover all aspects of this basic question.

Example: “PHP stands for Hypertext Preprocessor. It is a web-based scripting language. This language is used to execute scripts for creating web pages and web apps. The syntax of this language resembles Perl or C.”

Related: What Does a PHP Developer Do? (Responsibilities and Salary)

2. Describe your experience working with PHP.

With this question, the interviewer is trying to understand the depth of your experience working with PHP. They want to gauge whether you have the kind of experience that the role requires. It is important to remember that you may have worked on all kinds of PHP projects, but highlighting the ones that relate to the role on offer would fetch you the maximum value out of this question.

When answering this question, relate your work experience with the requirements of the role. Highlight those parts of your experience that are similar to the work you would be doing as part of this job.

Example: “In my previous job, I was asked to create a web portal for online orders. I used PHP scripting language to generate JavaScript. I programmed the PHP scripts to generate JavaScript upon execution and the JavaScript only had to be accessed by a browser to execute. This made it a good choice for creating frontend features that allowed end-users to shop for products. As a result, the company had a reliable, platform-independent customer portal that helped them increase their sales.”

Related: Top PHP Coding Tutorials and Courses For Beginners And Experts

3. Discuss how PHP is executed

This question seems straightforward and that makes answering it well very important. PHP is a scripting language that can be executed in the command-line interface. But, it is also a series of scripts that can generate code that is executed in different ways. You are required to cover both these aspects in your answer.

The interviewers ask this question to understand the depth of your knowledge of PHP. They also want to see how you apply soft skills like problem-solving and critical thinking. To answer this question well, describe the execution process briefly and highlight how other programming languages can also be executed through PHP.

Example: “Traditionally, PHP is executed when the specific file name of the script is used in the command-line interface or CLI. But, PHP can be used to generate other programming languages like JavaScript. In the case of JavaScript, PHP generates the code and this code is then executed when it is accessed by a browser.”

Related: 8 PHP Logical Interview Questions With Example Answers

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

'echo' and 'print' are very similar to each other. Both are used to output data onto the screen. For this reason, the interviewers often ask this question in PHP interviews. This question helps them understand how clear you are with the basic concepts and if you can answer this question with clarity.

To answer this question, briefly explain the two functions and highlight all the application-based differences between the two.

Example: “'echo' and 'print' are two similar functions used to output data onto a screen in PHP. 'echo' is a little faster than 'print' and can take more than one parameter. But, such use cases are rare. 'echo' has no return value. 'print', on the other hand, has a return value of one. This means we can use it in expressions. 'print' can take one argument only.”

5. What is the difference between 'for' and 'foreach'?

'for' and 'foreach' are the two types of loops in PHP. Both these loops have their own specific applications. The interviewer is looking to test your understanding of these loops and how these differ in their application through this question. To answer this question, briefly explain the differences between the two loops and mention the specific details of how they are used in a PHP program.

Example: “The 'foreach' loop is used for the implementation of associative arrays in PHP. On the other hand, the 'for' loop is used with variables. If we talk about how the two loops work, the 'for' loop works by the end of the loop condition, whereas the 'foreach' loop works at the end of the array count.”

Related: What Is Computer Programming? (With Definition And Types)

6. What are the benefits of using PHP?

The interviewers ask this question to understand your practical experience of having used PHP. To answer this question well, you would need a proper understanding of some of the benefits of PHP over other languages used for web-based coding. Such an understanding develops over time with experience and the interviewers know that. So, make sure your answer is more than the definitions you see in books and highlights your experience with PHP.

Example: “PHP is a scripting language, which means it is a series of scripts that can be programmed to do several things upon execution, including coding in other languages that are more end-user friendly. PHP scripts are typically used to create the features of a website or web app. PHP is open-source. This means it is not contingent on manufacturer updates or proprietary limitations. PHP is platform-independent. This means it can run across a variety of platforms and does not need a proprietary platform to run. A large number of databases support PHP integration. PHP is also compatible with most mainstream servers. PHP is very affordable. It is not costly to develop and maintain.”

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Tips For Doing Well In Your PHP Interview

Here are a few tips to help you do better in your PHP interview:

Use the STAR method

As a PHP developer, you would require to display creativity, critical thinking and problem-solving skills. For this reason, it becomes very important that your interview answers showcase these skills effectively. You may be highly proficient in PHP, but the way you present your answers would help you stand out from the other candidates.

One method you may use for framing your answers effectively is the STAR method. STAR stands for Situation, Task, Action and Result. This method requires you to provide a direct answer and explain a related challenge you faced in past work. You can use the STAR interview response framework to structure your answer by addressing the following:

  • Situation: Briefly explain the issue you were dealing with in a positive, constructive way.

  • Task: Explain your role in the situation.

  • Action: Explain what you did to resolve or address the situation.

  • Result: Explain your learnings and how your actions resulted in a positive impact on the business.

Related: How to Prepare for a Job Interview

Practice coding exercises

Some PHP interviews may require you to take a written test, an online test or work out a code-related problem on a whiteboard. This is a common practice in development interviews, as it serves to test your practical coding skills.

In some cases, interviewers may provide a code snippet and ask you to fix a specific piece of PHP code. Other iterations of this concept include asking you to write a code snippet, defining the output of a given piece of code, list values in a code or otherwise identify a problem.

To prepare for such exercises for your interview, you can access the different online resources that provide such coding challenges. You can practice by solving these challenges and if your results show that you need improvement in some specific areas, you can then focus on those particular areas of PHP. You can also join some coding classes to work on your PHP skills.

Related: How To Improve Coding Skills (With Practical Tips And Advice)

Practice mock interviews

Once you are confident with the answers you have prepared and are proficient with the language, find some practice interview questions online. Many of these questions would quiz you on your vocabulary, level of fluency and problem-solving skills. You can then practice these questions in a mock interview setting with your friends or family members' help.

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