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Table of contents
1.
Introduction
2.
CodeIgniter Interview Questions for Freshers
2.1.
1.What is Codeigniter?
2.2.
2. What are the salient features of Codeigniter?
2.3.
3. What are Hooks in Codeigniter? List some of them.
2.4.
4. What is routing in Codeigniter?
2.5.
5. What command is used to connect models to the database manually?
2.6.
6. What are the components of the default URL pattern in Codeigniter?
2.7.
7. What is an inhibitor in Codeigniter?
2.8.
8. What are helpers? And what are their types in Codeigniter?
2.9.
9. Differentiate between a helper and a library in Codeigniter?
2.10.
10. List some advantages of Codeigniter.
2.11.
11. What are some databases supported by Codeigniter Framework?
3.
CodeIgniter Interview Questions for Experienced 
3.1.
12. What is the significance of a model in Codeigniter? 
3.2.
13. What are controllers in Codeigniter?
3.3.
14. Explain how to load a model in Codeigniter?
3.4.
15. Explain how you can activate CSRF(Cross-Site Request Forgery) in Codeigniter?
3.5.
16. What are Views in Codeigniter?
3.6.
17. What are the drivers in Codeigniter?
3.7.
18. How do you enable Hook in Codeigniter?
3.8.
19. What is the command used to initialize a driver in Codeigniter?
3.9.
20. What is the syntax for extending a class in Codeigniter?
3.10.
21. Can you load multiple helper functions in a single command in Codeigniter? If so, how?
4.
Frequently Asked Questions
4.1.
What is Codeigniter?
4.2.
What are the common topics of questions in the Codeigniter Interview Question?
4.3.
Can you use core PHP functions in Codeigniter Interview Questions?
4.4.
Why use Codeigniter over other PHP Frameworks?
4.5.
What is MVC?
5.
Conclusion
Last Updated: May 20, 2024

CodeIgniter Interview Questions

Author Teesha Goyal
0 upvote

Introduction

This article will discuss the most common Codeigniter interview questions to help you prepare. These questions are among the most asked Codeigniter interview questions.

Codeigniter is a framework used for developing web development on PHP. So, most Codeigniter interview questions are about working, functions, features, database handling, and routing in Codeigniter.

Let's continue with some of the top Codeigniter interview questions.

CodeIgniter Interview Questions for Freshers

1.What is Codeigniter?

Codeigniter is a powerful Model-View-Controller(MVC) based framework on PHP used to develop web applications. It is an open-source framework, so it doesn't require licenses or permissions. It provides an easy toolkit for the developers, making it more beginner-friendly than other PHP frameworks.   

2. What are the salient features of Codeigniter?

Following are the salient features of Codeigniter:

  1. Codeigniter is an open-source framework and free to use.
  2. Framework with a small footprint. It makes the development, deployment, and update easier.
  3. Based on MVC(Model-View-Controller).
  4. Clear and short documentation.
  5. Strong Security 
  6. Build super-fast web applications. 
  7. Extendable. Several libraries and helpers can be added.

3. What are Hooks in Codeigniter? List some of them.

Hooks in Codeigniter is a feature to change or alter the inner functionalities and working of the framework without compromising the core files. The hooks are defined in the application/config/hooks.php file.
Some of the hooks in Codeigniter are:

  1. pre_system
  2. pre_controller
  3. post_system
  4. post_controller
  5. cache_override
  6. display_override

4. What is routing in Codeigniter?

Routing is a technique provided by Codeigniter by which you can define your URLs according to your requirements instead of using the default URLs. So, when a URL is typed by the user that matches the URL you defined, it automatically directs to the controller or associated classes. 
There are specific rules and protocols to be followed while defining the URLs; they are defined inside the application/config/routes.php file.

5. What command is used to connect models to the database manually?

The following command is used to connect models to the database in Codeigniter manually:
$this->load->database();  

6. What are the components of the default URL pattern in Codeigniter?

The default URL pattern in Codeigniter has four components to be defined in their specific order.
An example of a default URL in Codeigniter is: 
http://ServerName/ControllerClassName/ControllerFunctionName/parameters.
The four components of the default URL pattern are: 

  1. ServerName
  2. ControllerClassName
  3. ControllerFunctionName
  4. FuntionParameters

7. What is an inhibitor in Codeigniter?

An inhibitor is a Codeigniter specialist class that primarily serves to handle errors. It is mainly composed of functions like set_error_handler, set_exception_handler, and register_shutdown_function, which are helpful in handling parsing errors, exceptions, and fatal errors.

8. What are helpers? And what are their types in Codeigniter?

In Codeigniter, a helper is a group of functions that execute a specific task. These functions can be loaded to your application to aid you in performing a specific task without actually writing the code yourself in the program.
There are following three types of helpers in Codeigniter:

  1. URL Helpers
  2. Text Helpers
  3. Cookies Helpers

9. Differentiate between a helper and a library in Codeigniter?

A library is a class that holds various functions that perform tasks in a specific domain. It is necessary to create an instance of the class to use the various functionalities of the library. It is written in the object-oriented programming paradigm.
A helper is a group of functions that perform specific tasks. All helper functions are independent of each other. They don't need to be written in the OOP paradigm. They can be invoked just like any other PHP function.

10. List some advantages of Codeigniter.

  1. Greate for handling errors and bug fixes.
  2. It provides customizability.
  3. Easy to use
  4. User-friendly interface
  5. Community support
  6. Fast Development
  7. Better search engine optimization
  8. Security 
  9. Built-in libraries

11. What are some databases supported by Codeigniter Framework?

Codeigniter Framework supports MySQL (5.1+), CUBRID, ODBC, Oracle, PostgreSQL, and Interbase/Firebird.

CodeIgniter Interview Questions for Experienced 

12. What is the significance of a model in Codeigniter? 

To interface with the database, a model is used. The model is responsible for retrieving data from the database table whenever a user requests certain data from the application. It also displays the data structure, from which you may input, edit, remove, and retrieve information.

13. What are controllers in Codeigniter?

The controller is responsible for the working of the Codeigniter application. It acts as a link between the model and the view. It takes the user's request and effectively manages it by displaying the model's outcome. With the help of the view component, it presents the user with the records.

14. Explain how to load a model in Codeigniter?

To load a model in Codeigniter, you can run the following command:
$this->load->model (‘Name’);

15. Explain how you can activate CSRF(Cross-Site Request Forgery) in Codeigniter?

The CSRF(Cross-Site Request Forgery) ensures protection in Codeigniter. You can activate CSRF in your program by setting the CSRF token to true in your application/config/config.php file. Following is the command to activate CSRF:
$config [ 'csrf_protection'] = TRUE;

16. What are Views in Codeigniter?

A View is equivalent to a website. It contains the data that is displayed to the user. A view is also found in the header and footer of a webpage. You may use an RSS feed and a user interface to represent the view page.

17. What are the drivers in Codeigniter?

A Driver is a particular type of library that can have one parent class and any number of child classes. In a driver library, the child classes can access the parent class functions but not siiblings' functions. 
Drivers are located in the system/libraries folder, in a folder with the same name as the parent library class. There's also a subdirectory called drivers inside that folder, which includes all available child class files. The behavior of the parent classes is modified in the child classes.

18. How do you enable Hook in Codeigniter?

To activate the hook, navigate to the application/config/config.php/ file and change it to True as shown below:
$config['enable_hooks'] = TRUE;  

19. What is the command used to initialize a driver in Codeigniter?

The below command is used to initialize a driver in Codeigniter:
$this->load->driver('driver_name');  

20. What is the syntax for extending a class in Codeigniter?

The extends keyword is used to extend a class in Codeigniter. Following is the syntax:
Class Drived_class extends Base_class{
}

21. Can you load multiple helper functions in a single command in Codeigniter? If so, how?

You can load multiple helper functions using a single command in Codeigniter. To do so, we have to create an array of helper functions and pass this array to load multiple.  
Example:
$this->load->helper(  
array('func1', 'func2', 'func3', ‘func4’) 
);

Must Read Web Developer Interview Questions

Frequently Asked Questions

What is Codeigniter?

Codeigniter is a powerful Model-View-Controller(MVC) based framework on PHP used to develop web applications. It is an open-source framework, so it doesn't require licenses or permissions.

What are the common topics of questions in the Codeigniter Interview Question?

Codeigniter is a framework used for developing web development on PHP. So, most of the Codeigniter interview questions are about working, functions, features, database handling, and routing in Codeigniter.

Can you use core PHP functions in Codeigniter Interview Questions?

Yes, as Codeigniter is a framework of PHP, you can use all the functionalities of core PHP in a Codeigniter program to build web applications.

Why use Codeigniter over other PHP Frameworks?

Codeigniter is the most simple and beginner-friendly out of all other PHP frameworks for web development. It is based on MVC(Model-view-controller) pattern. It provides security and extensibility.

What is MVC?

MVC(Model–view–controller) is a system design pattern that divides related application logic into three interconnected pieces and is often used for designing user interfaces.

Conclusion

This article discussed some of the most common Codeigniter Interview Questions. We have discussed also provided the solutions to the mentioned Codeigniter Interview Questions.

I hope you would have gained a better understanding of these topics now!

Recommended Readings:

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