CodeIgniter Interview Questions and Answers

Last updated on Feb 06, 2023
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CodeIgniter Interview Questions

CodeIgniter is a PHP open-source web development framework for building dynamic websites. Based on the MVC development pattern, Codeigniter can be modified to use the HMVC pattern. This pattern allows developers to maintain controller, view, and models in a sub-directory format. This framework is known for its higher speed as compared to other PHP frameworks. If you are looking for Codeigniter interview questions, we can help you!

A Quick Overview of CodeIgniter
What is Codeigniter? It is a PHP open-source web development framework for building dynamic websites. Based on the MVC development pattern, Codeigniter can be modified to use the HMVC pattern.
Latest Version 4.0, released on September 3, 2019
Stable Version 3.1.10, released on January 16, 2019
Created By EllisLab
Written in PHP
License MIT License

Most Frequently Asked CodeIgniter Interview Questions

Here in this article, we will be listing frequently asked CodeIgniter Interview Questions and Answers with the belief that they will be helpful for you to gain higher marks. Also, to let you know that this article has been written under the guidance of industry professionals and covered all the current competencies.

Q1. What is Codeigniter & why it is used for?
Answer

It is a PHP open-source web development framework which is used for building dynamic websites.

Q2. What is the latest version of Codelgniter? Lists its new features.
Answer

4.0 is the latest version of the Codelgniter framework. This version is released on September 3, 2019.

Here are some new features that support Codelgniter

  • URL Helper
  • Query builder
  • Email Library
  • Form Validation Library
  • Session Library

Codelgniter updated these modules to enhance features.

Q3. List the databases supported by Codeigniter?
Answer

Currently Codeigniter supports these databases that's are given below :-

  • MySQL
  • Oracle
  • PostgreSQL
  • SQLite
  • ODBC
  • Firebird etc
Q4. What is hooks and how we can configure hooks in CodeIgniter?
Answer

It is a type of events which can be called before and after the execution of a program in CodeIgniter. For example Hooks can be used where we need to check whether a user is logged in or logged out before the execution of controller.

It can be globally enabled or disabled by setting in the application/config/config.php page

It can be defined in application/config/hooks.php page. In CodeIgniter each hook is specified like an array with this prototype:

Q5. How to add or load a model in CodeIgniter?
Answer

You can do it with this $this->load->model("ModelName");

Q6. How to load a view in CodeIgniter?
Answer

You can use this $this->load->view('name'); to load a view in CodeIgniter.

Q7. What is the default controller used in CodeIgniter? How we can change it?
Answer

In CodeIgniter when a specified file in the default controller loaded by default when there is no file name mentioned in URL. By default "welcome.php" file is loaded after installing CodeIgniter.

Yes, we can change it from application/config/routes.php. We have to pass our controller name which we want to load by default in $route['default_controller']

For example, now the frontend is the default controller $route['default_controller'] = 'Frontend'; from now. Interview questions on Codeigniter are always a level up and thus a little tough to crack.

Q8. Explain the basic Url Structure in Codeigniter?
Answer

The basic URL structure is bestinterviewquestion.com/class/function/ID.

Here class represents controller's class that needs to be invoked.
Here "function" is name of method which is called.
ID is an additional parameter that is passed to controllers.

Q9. What do you mean by helper in CodeIgniter?
Answer

Helpers is collection of functions which help us with different tasks as name suggested. Every helper function is used to performs specific task with no dependence on other functions.

CodeIgniter provide various types of helper class like url_helper, captcha_helper ,email_helper. All these helpers are located in system/helper.

By default CodeIgniter does not load any Helper files. First step is to be load Helper. After loaded it is available in all controller and views.

 

How we can load a Helper : $this->load->helper('name');
Here "name" is file name of helper.

How to load multiple Helpers at one time.
$this->load->helper(array('helper1', 'helper2', 'helper3')); // Here helper1,helper2,helper3 are different helper's name.

Q10. Explain the difference between helper and library in CodeIgniter?
Answer

Helper is a set of Common functions which we can use within Models, Views, Controllers everywhere. Once we include that file then we can get access to the functions.
Library is a class which we need to make an instance of the class by $this->load->library() this function.

NOTE : A library is used in object-oriented context but a helper is more suitable to be used within the Views

History of Codeigniter

The first version was released in Feb 2006 by EllisLab.

Advantages of Codeigniter

If you are preparing for Codeigniter interview questions, do memorize the powers of CodeIgniter.

  • Easy to learn, handle and customize
  • Flexible and easy to configure
  • Amazing Active Record Implementation
  • Best-in-class documentation
  • Discount, Offers, Coupons and Options and Properties
  • Extensive user base
Reviewed and verified by Umesh Singh
Umesh Singh

My name is Umesh Singh having 11+ experience in Node.JS, React JS, Angular JS, Next JS, PHP, Laravel, WordPress, MySQL, Oracle, JavaScript, HTML and CSS etc. I have worked on around 30+ projects. I lo...