Preparing for a PHP job interview? Whether you're a beginner trying to get your first job or an experienced developer aiming for a senior role, brushing up on PHP interview questions is essential. In this blog, we’ll cover common questions across all levels, from basic variables to advanced object-oriented programming (OOP) concepts. Plus, we’ll show you how to practice your code using an online PHP compiler, so you can get hands-on experience without needing a local setup.

Why PHP Interview Preparation Matters

PHP is still one of the most widely used server-side scripting languages in web development. It powers content management systems like WordPress and frameworks like Laravel and Symfony. Employers are always on the lookout for developers with strong PHP skills—so whether you're interviewing for a backend developer role or a full-stack position, solid PHP knowledge is a must.

Getting Started: Beginner PHP Interview Questions

Here are some common beginner-level questions that often come up:

1. What is PHP?

Answer: PHP (Hypertext Preprocessor) is an open-source server-side scripting language designed specifically for web development. It is embedded in HTML and is widely used to manage dynamic content, databases, session tracking, and more.

2. How do you declare a variable in PHP?

$name = "John";

$age = 25;

Variables in PHP start with a $ sign and are loosely typed, meaning you don’t need to declare a data type.

3. What are the different data types in PHP?

• String

• Integer

• Float

• Boolean

• Array

• Object

• NULL

4. How do you comment code in PHP?

// Single line comment

# Another single line comment

/* Multi-line

comment */

💡 Tip: Use an online PHP compiler like Tpoint Tech Online PHP Compiler

Mid-Level PHP Interview Questions

Once you’ve mastered the basics, you’ll face more technical and logic-based questions.

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

• == compares values regardless of type.

• === compares both value and type.

var_dump(5 == "5"); // true

var_dump(5 === "5"); // false

6. What are superglobals in PHP?

Superglobals are built-in variables that are always accessible:

• $_GET

• $_POST

• $_SESSION

• $_COOKIE

• $_FILES

• $_SERVER

• $_REQUEST

7. How is error handling done in PHP?

PHP uses functions like try, catch, throw, and finally for exception handling. For basic error reporting, error_reporting() and ini_set() can be used.

try {

// some code

} catch (Exception $e) {

echo 'Caught exception: ', $e->getMessage(), "\n";

}

8. How do you include files in PHP?

• include 'file.php';

• require 'file.php';

The difference? require will produce a fatal error if the file is missing, while include will produce a warning.

Advanced PHP Interview Questions: OOP Focus

Object-Oriented Programming (OOP) is crucial for modern PHP development. Here are some key OOP questions:

9. What are the four pillars of OOP in PHP?

1. Encapsulation

2. Abstraction

3. Inheritance

4. Polymorphism

10. How do you define a class and an object in PHP?

class Car {

public $brand;

function setBrand($brand) {

$this->brand = $brand;

}

$myCar = new Car();

$myCar->setBrand("Toyota");

11. What are access modifiers in PHP?

• public: accessible everywhere

• protected: accessible within the class and subclasses

• private: accessible only within the class

12. What is a constructor in PHP?

A constructor is a special function automatically called when an object is created.

class Person {

function __construct() {

echo "Constructor called!";

}

13. What is the difference between abstract class and interface in PHP?

• Abstract classes can have method definitions and properties.

• Interfaces can only have method declarations (no implementations).

Practice Makes Perfect: Use an Online PHP Compiler

Don’t just read the answers—write and run the code. With an online PHP compiler, you can:

• Test snippets instantly

• Avoid the hassle of local server setup

• Practice for interviews on the go

Some popular options:

• PHP Fiddle

• OneCompiler

• TutorialsPoint PHP Compiler

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Final Thoughts

Reviewing these PHP interview questions—from basic variables to object-oriented programming—will give you a solid edge in your next interview. Pair your study time with an online PHP compiler for hands-on practice and you'll be more than ready.

🔑 Key Takeaways:

• Master PHP basics like variables, syntax, and data types.

• Practice mid-level questions around control flow, functions, and error handling.

• Understand OOP concepts thoroughly.

• Use online compilers to experiment with and test your code live.

Ready to ace your interview? Start coding now—no setup required!

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