• Skip to main content
  • Skip to secondary menu
  • Skip to primary sidebar
  • Skip to footer
  • Home
  • About Me
  • Connect
  • Credits
  • Privacy Policy
  • Sitemap
Surendra Soni

Surendra Soni

Learn Programming With Me...

First, solve the problem. Then, write the code.

– John Johnson

  • Articles
  • Recourses
  • Errors
  • Codeigniter

Common questions Asked about CodeIgniter 4

Published on August 13, 2023, Last Updated on August 14, 2023 by Surendra Soni Leave a Comment

We are providing 25 common questions about CodeIgniter 4, along with answers, detailed explanations, and example code snippets. Please do comment you wanted discuss more about it.

1. What is CodeIgniter 4?

Answer: CodeIgniter 4 is a lightweight, high-performance PHP framework for building web applications. It follows the Model-View-Controller (MVC) architecture.

2. How do you install CodeIgniter 4?

Answer: You can install CodeIgniter 4 using Composer. Run the following command:

composer create-project codeigniter4/appstarter my_project
Bash

3. How to define a basic route in CodeIgniter 4?

Answer: You can define a route in the app/Config/Routes.php file.

$routes->get('welcome', 'Home::welcome');
PHP

4. How to create a controller in CodeIgniter 4?

Answer: Controllers can be created in the app/Controllers directory. Here’s an example:

namespace App\Controllers;

class Home extends BaseController
{
    public function welcome()
    {
        return view('welcome_message');
    }
}
PHP

5. How to load a model in CodeIgniter 4?

Answer: You can load a model using the model() method.

public function index()
{
    $this->model('UserModel');
    // Use the UserModel
}
PHP

6. How to handle database migrations in CodeIgniter 4?

Answer: You can create a migration file using the following command:

php spark make:migration create_users_table
Bash

Then, implement the up and down methods in the migration file:

public function up()
{
    $this->forge->addField([
        // Define fields here
    ]);
    $this->forge->createTable('users');
}

public function down()
{
    $this->forge->dropTable('users');
}
PHP

To run migrations:

php spark migrate
Bash

7. How to use validation in CodeIgniter 4?

Answer: You can define validation rules in a controller. Here’s an example:

public function create()
{
    $validation = \Config\Services::validation();
    $validation->setRule('username', 'required|min_length[5]');

    if ($this->request->getPost() && !$validation->withRequest($this->request)->run()) {
        return view('create', ['validation' => $validation]);
    }
}
PHP

8. How to create RESTful API in CodeIgniter 4?

Answer: CodeIgniter 4 provides support for building RESTful APIs. Here’s a basic example:

namespace App\Controllers;

use CodeIgniter\RESTful\ResourceController;

class Users extends ResourceController
{
    public function index()
    {
        // Return a list of users
    }
}
PHP

9. How to handle sessions in CodeIgniter 4?

Answer: Sessions can be used with the session() function:

// Setting a session value
session()->set('username', 'John');

// Getting a session value
$username = session()->get('username');
PHP

10. How to implement CSRF protection in CodeIgniter 4?

Answer: CSRF protection is enabled by default in CodeIgniter 4. You can verify this in the app/Config/Filters.php file. Include {csrf_field()} in your forms to generate a hidden CSRF token field.

<form method="post">
    <?= csrf_field() ?>
    <!-- form fields -->
</form>
HTML

11. How to configure base URL in CodeIgniter 4?

Answer: You can configure the base URL in the app/Config/App.php file:

public $baseURL = 'http://example.com/';
PHP

12. How to use the CodeIgniter 4 email library?

Answer: You can send emails using the Email class:

$email = \Config\Services::email();
$email->setFrom('[email protected]', 'Your Name');
$email->setTo('[email protected]');
$email->setSubject('Email Test');
$email->setMessage('Testing the email class.');

$email->send();
PHP

13. How to upload a file in CodeIgniter 4?

Answer: You can use the File class to handle file uploads:

$file = $this->request->getFile('file');
if ($file->isValid() && !$file->hasMoved()) {
    $file->move('./uploads');
}
PHP

14. How to handle pagination in CodeIgniter 4?

Answer: CodeIgniter 4 provides the Pager library to create paginated data:

// In Controller
$pager = \Config\Services::pager();
$data['pagination'] = $pager->links();

// In View
echo $pagination;
PHP

Filed Under: Codeigniter Tagged With: Codeigniter 4, Interview Questions

Email Newsletter

Like what you read here in this blog post?
Get more like it delivered to your inbox daily.

your information is safe with us, we will not disclose it in any one.

One request?

If you feel this article worth sharing with your buddies, then please share. It’ll be very helpful for me. SHARING IS πŸ’• CARING

Affiliate disclosure: In full transparency – some of the links on our website are affiliate links, if you use them to make a purchase we will earn a commission at no additional cost for you (none whatsoever!).

About Surendra Soni

Hi, I'm Surendra Soni, a πŸš€ full-stack developer from Bangalore with 8️⃣ years of experience. I specialize in front-end and back-end technologies, and love finding πŸŽ‰ creative solutions for my clients. Let's work together to bring your ideas to life! πŸ™Œ. Let's Connect

Connect With Me :

Reader Interactions

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Primary Sidebar

More to See

Common questions Asked about CodeIgniter 4

August 13, 2023 By Surendra Soni

How to Show Different Number of Posts on Home and Sub Pages on Genesis Child Theme. [Specially Eleven40 Theme]

August 13, 2023 By Surendra Soni

Tags

Cloud Codeigniter 4 coding concept Error Fixes Fixes genesis framework Hosting How to Interview Questions learning SSL WordPress Plugin

Footer

About Me

πŸ‘‹ Hi there! My name is Surendra Soni, and I’m a πŸš€ full-stack developer based in Bangalore, India with over 8️⃣ years of experience in the field. I’m passionate about sharing my πŸ’» technical expertise with you and that’s why I created this website.

If you are interested you can [Read more about me.]

Recent

  • Akismet Spam Protection Plugin: Benefits, Setup, and Free Implementation
  • Common questions Asked about CodeIgniter 4
  • How to Show Different Number of Posts on Home and Sub Pages on Genesis Child Theme. [Specially Eleven40 Theme]
  • SSL Renewal Error PHP Fatal error: Uncaught GuzzleHttp – v4
  • Programming Logic & Techniques Explained With Example

Explore

  • Home
  • About Me
  • Connect
  • Credits
  • Privacy Policy
  • Sitemap

Copyright © 2023 Β· Surendra Soni | All Rights Reserved.