Top 26 Codeigniter Interview Questions to Test Your Skills

In this article, we’ll see list of Codeigniter Interview Questions.

CodeIgniter is a popular PHP framework for developing web applications. It is known for its simplicity, flexibility, and performance. If you are interviewing for a job that requires knowledge of CodeIgniter, you can expect to be asked a number of questions about the framework.

Its simplicity, speed, and extensive library of features have made it a popular choice among PHP developers.

If you have an upcoming CodeIgniter interview, it’s essential to be well-prepared. To assist you in your preparation, we have compiled a list of ten unique CodeIgniter interview questions that will help you showcase your expertise and stand out from the competition.

Codeigniter Interview Questions

Here are some of the most common CodeIgniter interview questions:

1) What Is Codeigniter?

Codeigniter is an open-source framework for developing websites on PHP. It is loosely based on the MVC pattern, and it is easy to use compared to other PHP frameworks.

CodeIgniter contains libraries, a simple interface, and a logical structure to access these libraries, plug-ins, helpers, and some other resources which solve the complex functions of PHP more easily maintaining high performance.

2) How to do a 301 redirect in Codeigniter?

We can use a redirect helper to do 301 redirects in Codeigniter.Syntax :

 redirect($uri = '', $method = 'auto', $code = NULL)

Parameter:

    $uri (string) – URI string
    $method (string) – Redirect method (‘auto’, ‘location’ or ‘refresh’)
    $code (string) – HTTP Response code (usually 302 or 303)

3) What Are Hooks In Codeigniter?

The Hook is a feature in CodeIgniter that provides a way to change the inner working of the framework without hacking the core files. It facilitates you to execute a script with a particular path within the CodeIgniter. Usually, it is defined in the application/config/hooks.php file.

4) What are CodeIgniter security methods?

CodeIgniter security methods help to create a secure application and process input data. The methods are given below:

  • XSS filtering
  • CSRF (Cross-site Request Forgery)
  • Class reference

5) What is a CSRF attack in CodeIgniter?

A CSRF attack forces a logged-on victim’s browser to send a forged HTTP request, including victim’s session cookie and other authentication information, to a web application.

For example, suppose you have a site with a form. An attacker could create a bogus form on his site. This form could contain hidden inputs and malicious data. This form is not sent to the attacker’s site, in fact, it comes to your site. Thinking that the form is genuine, your site process it.

Now suppose that the attacker’s form point towards the deletion form in your site. If a user is logged in and redirected to the attacker’s site and then performs the search, his account will be deleted without knowing him. That is the CSRF attack.

6) What are the XSS security parameters?

XSS stands for cross-site scripting. Codeigniter contains a cross-site scripting hack prevention filter. The XSS filter targets methods to trigger JavaScript or other types of suspicious code. If it detects anything, it converts the data to character entities.

7) Why is URL routes need to be configured?

There are many purposes for which the URL routes are configured.

  1. To improve the number of page visits.
  2. To hide the code complexities from the user.

8) What are Different Types Of Hooks In Codeigniter?

Followings are Different types of hook points in Codeigniter:

  • post_controller_constructor
  • pre_controller
  • post_sytem
  • pre_system
  • cache_override
  • display_override
  • post_controller

9) How many types of messages can you log in to Codeigniter?

There are three message types in Codeigniter. They are :

  • Error Messages. These are actual errors, such as PHP errors or user errors.
  • Debug Messages. These are messages that assist in debugging. For example, if a class has been initialized, you could log this as debugging info.
  • Informational Messages. These are the lowest priority messages, simply giving information regarding some process.

10) How to connect multiple databases in CodeIgniter?

To connect more than one database simultaneously, do the following,

$db1 = $this->load->database('group_one', TRUE);

$db1 = $this->load->database('group_two', TRUE);

11) What Is Inhibitor In Codeigniter?

Inhibitors are basically Error handling classes that are associated with CodeIgniter and these are implemented using different PHP functions.

12) What are the Helpers in CodeIgniter?

The Helpers are the group of functions in a specific category that helps to perform particular functions. There are many helpers in CodeIgniter that you can use according to your requirement. The major CodeIgniter helpers are URL Helpers that assist in creating links, Form Helpers that help you create form elements, Text Helpers to perform various text formatting routines, Cookie Helpers to set and read cookies, File Helpers to help you deal with files, etc.

13) How You Can Extend The Class In Codeigniter?

To extend the native input class in CodeIgniter, you have to build a file named application/core/MY_Input.php and declare your class with

Class MY_Input extends CI_Input {

}

14) What is the default URL pattern used in CodeIgniter?

In the default URL pattern, there are four main components in CodeIgniter. First, we have the server name followed by the controller class name. Then, we have the controller function name and at the end, there are function parameters. We can access the CodeIgniter using the URL helper.

Syntax- http://servername/controllerName/controllerFunction/parameter1/parameter2.

15) How to set the default time zone in CodeIgniter?

Add date_default_timezone_set(‘your timezone’); in index.php
CodeIgniter is the most sought-after framework of PHP when it comes to developing dynamic websites and web applications. Developers prefer it due to its speed. Cracking a CodeIgniter interview questions is not a cakewalk. So, the above questions have been curated keeping in mind the aspirants who are planning to ace the interview and win over their opponents. The answers to these questions are brief, crisp and up-to the mark.

16) What Are The Features Of Codeigniter?

  • It is a free, open-source PHP framework.
  • Unlike other frameworks that require huge file libraries, CodeIgniter is a light weighted framework that requires only a few small libraries.
  • It is fast as compared with any other framework of PHP.
  • CodeIgniter is extensible which can be easily extended using class extensions, helpers or system hooks.
  • It is based on MVC pattern and requires nearly zero configurations.

17) How To Access Config Variable In Codeigniter?

$this->config->item(‘variable name’);

18) How To Unset Session In Codeigniter?

$this->session->unsetuserdata(‘somename’);;

19) Explain Codeigniter File Structure?

The following are the folder structure that you’ll get when you download CodeIgniter-

Application- helpers, hooks, language, library, cache, models, views, third party, Controllers.

System– core, database, fonts, language, libraries.

20) What do you mean by CodeIgniter Library?

The CodeIgniter provides a different set of libraries and these are useful with the continues improvements and support of the application and also its corresponding enhancements. This is mainly located in the system->library section. There are different types of methods that can be used to create a library.

  1. The process to create a whole new library.
  2. The process to replace the native library.
  3. The process to extend the native library.

21) How can you print SQL statement in the CodeIgniter model?

$this>db>insertid();

22) What are CodeIgniter drivers?

These are a particular type of library that has a parent class and many child classes. These child classes have access to the parent class, but not to their siblings. Drivers are found in the system/libraries folder.

23) How Can You Use Aliases With Autoloading Models In Codeigniter?

We can auto load model like this:

$autoload[‘model’] = array(array(‘usersmodel’, ‘users’), array(‘newsmodel’, ‘news’), ‘categorymodel’);

24) How Can You Get-Random Records In Mysql Using Codeigniter?

We can use this:

$this->db->order_by(‘id’,’RANDOM’);

25) Who Developed Codeigniter?

Codeigniter was developed by EllisLab Inc.

26) Why Codeigniter Is Called As Loosely Based MVC Framework?

The reason behind this is we do not need to follow a strict MVC pattern while creating an application. We can also able to build with a model-only view and controllers are enough to build an application.

By familiarizing yourself with these ten unique CodeIgniter interview questions, you’ll be well-prepared to showcase your knowledge and expertise during your interview.

Remember to not only provide correct answers but also demonstrate your understanding of the underlying concepts and your ability to apply them in real-world scenarios. Good luck!

These are just a few of the most common CodeIgniter interview questions. If you are preparing for a CodeIgniter interview, it is a good idea to practice answering these questions. You can also find additional CodeIgniter interview questions online.

In addition to answering questions about CodeIgniter interview questions, you may also be asked about your experience with other PHP frameworks, your knowledge of web development, and your problem-solving skills. Be sure to highlight your skills and experience that are relevant to the job you are applying for.

If you can answer these CodeIgniter interview questions confidently, you will be well on your way to landing your dream job as a CodeIgniter developer.