Fresher Web Developer Interview Questions & Answers

Introduce yourself

Hi, I'm a web developer with hands-on experience building dynamic, secure, and user-friendly websites and web apps. Over the years, I've worked with various tools, frameworks, and coding paradigms that have helped me become efficient in both frontend and backend development.

What I've Learned from Experience

1. Writing clean and maintainable code is more valuable than clever hacks.
2. Security is a critical component of every web application.
3. Never stop learning technology evolves fast, and staying updated matters.
4. Understanding fundamentals (like OOP, procedural coding, security practices) is more important than just knowing frameworks.

What is OOP (Object-Oriented Programming)?

Object-Oriented Programming (OOP) is a programming paradigm based on the concept of "objects." These objects are instances of classes that can contain data in the form of fields (also known as attributes or properties) and code in the form of procedures (often known as methods).

Benefits of OOP:

1. Encapsulation: Keeps data safe from outside interference.
2. Inheritance: Allows new classes to inherit properties of existing ones.
3. Polymorphism: Methods can behave differently based on the object context.
4. Reusability: Encourages DRY (Don't Repeat Yourself) coding principles.

What is an Object and How Does It Work?

An object is a self-contained component that contains properties and methods. In PHP, you can create objects from classes like this:

class Car {
    public $color;
    
    function setColor($color) {
        $this->color = $color;
    }
}

$myCar = new Car();
$myCar->setColor("Red");

Objects are useful because they model real-world entities. In this example, $myCar is an object of the Car class, and it has its own state (color).

What is Cross-Site Scripting (XSS)?

Cross-Site Scripting (XSS) is a type of security vulnerability found in web applications. It allows attackers to inject malicious scripts into content that other users see.

Types of XSS:

1. Stored XSS: The script is saved on the server (e.g., in a database).
2. Reflected XSS: The script is part of the URL or input, reflected back.
3. DOM-based XSS: Vulnerability lies in client-side scripts.

How to Prevent XSS:

1. Always escape HTML output using htmlspecialchars() in PHP.
2. Use frameworks that sanitize inputs by default.
3. Apply Content Security Policy (CSP) headers.

What is SQL Injection?

SQL Injection is an attack where malicious SQL code is inserted into an input field to manipulate the database.

Example:

// Vulnerable code
$sql = "SELECT * FROM users WHERE username = '$username'";

Prevention:

1. Use prepared statements or PDO in PHP:

$stmt = $pdo->prepare("SELECT * FROM users WHERE username = ?");
$stmt->execute([$username]);

1. Validate and sanitize all user inputs.
2. Use ORMs like Eloquent or Doctrine in frameworks.

Bootstrap 4 vs Bootstrap 5: Key Differences

Summary:

Bootstrap 5 is lighter, faster, and more modern, making it a better choice for new projects.

What is Procedural PHP?

Procedural PHP is the traditional way of writing PHP code in a step-by-step (top to bottom) manner using functions and logical statements. Unlike OOP, it doesn't involve classes or objects.

Example:

function add($a, $b) {
    return $a + $b;
}
echo add(5, 10);

Procedural code is easier for beginners but less scalable than OOP in large applications.

Do I Use PHP Frameworks?

Yes, I've worked with:

1. Laravel Great for MVC architecture, Eloquent ORM, Blade templating.
2. CodeIgniter Lightweight, good for small to medium apps.
3. Symfony More enterprise-focused, great for reusable components.

Frameworks help structure code, increase productivity, and include built-in security features.

Do I Use CSS Frameworks?

Absolutely! Here are my go-to choices:

1. Bootstrap For responsive design and quick prototyping.
2. Tailwind CSS For utility-first approach and performance.
3. Bulma Lightweight and easy to customize.

Each framework has its use-case based on project size, complexity, and team preference.

How to Avoid SQL Injection?

1. Use prepared statements with PDO or MySQLi.
2. Always validate and sanitize user input.
3. Use ORMs where possible.
4. Limit database permissions (e.g., no DROP or DELETE rights unless required).

What is CSRF (Cross-Site Request Forgery) and How to Protect?

CSRF tricks the user into executing unwanted actions on a site where they are authenticated.

Prevention:

1. Use CSRF tokens in forms.
2. Verify HTTP Referer headers.
3. Implement SameSite cookies.

Most modern frameworks like Laravel include CSRF protection out of the box.

What is Script Injection and How to Prevent It?

Script injection is similar to XSS, where attackers inject malicious JavaScript or other scripts.

Prevention:

1. Sanitize input and encode output.
2. Use Content Security Policies.
3. Avoid using eval() or innerHTML unsafely in JavaScript.

Additional Related Web Development Questions & Answers

What is MVC Architecture?

MVC stands for Model-View-Controller. It separates business logic (Model), UI (View), and request handling (Controller). Laravel and CodeIgniter are based on MVC.

How Do You Improve Website SEO?

1. Use semantic HTML tags (, , )
2. Create meta tags, titles, and descriptions.
3. Optimize for mobile devices and fast loading speed.
4. Use structured data and alt tags on images.

What is RESTful API?

A RESTful API uses HTTP methods to perform CRUD operations:

1. GET Retrieve data
2. POST Create
3. PUT Update
4. DELETE Remove

Final Thoughts

As a full-stack developer, my goal is to write secure, maintainable, and scalable code while providing a great user experience. Whether it's securing your backend, optimizing the frontend, or integrating APIs, I bring real-world experience and passion to the table.

Other Questions

1. How to create a API ?
2. What is Special State of Element ?
3. Objects in JavaScript ?
4. Arrays in JavaScript ?
5. Arrow Function and Why it use ?
6. Canvas and how to measure Canvas height and weight ?
7. Void Tags in HTML ?
8. Semantic and Non-Semantic Tags ?
9. How to create Array ?
10. Why Object use for data ?
11. Why UX is Important for a Website ?
12. What is Section Tag ?

Best of Luck for Your Interview. These Questions asked in Urban Unit's Fresher Web Developer Interview.