Codeigniter Interview Question Answer
1 - What is Helper in Codeigniter?
Helper is simply a collection of functions, these function is called procedural functions.
so for use of helper first load helper file
In Codeigniter there are two type of helper
(a)- User define helper- we create in application->helpers
(b)- Provided by Codeigniter like Form Helper, URL Helper etc.
we can view these helper in system folder.
2 - How many type of database supported by codeigniter frameworks?
3 - What is the difference between helper and library in codeigniter?
Helper is functions, we are just inclue helper file then we can call function Models,Views and Controllers.But Library is class, we create instance of the class by $this->load->library() then we can call any function in Models,Views and Controllers.
4 - Explain CodeIgniter Url Structure
http://www.ittrainingonline.co.in is a domain
user is a controller name
tutorial is a function name
codigniter and 81 both are querystring value
5 - How to Prevent SQL injection in Codeigniter?
There are three way to prevent SQL injection.
1- Active Record Class
2- Escaping Queries
$query = "select * from info where name=".$this->db->escape($name);
3- Query Binding
$sql = "select * from info WHERE id=? and name=?";
$this->db->query($sql, array('35', 'shishir sharma'));
6 - What are the hooks in CodeIgniter?
Hook file run before execution of webapplication after execution of the webapplication.
For creating hook there are three steps.
1- Enable hook in application->config->config.php file.
2- Specify code to run on application->config->hooks.php
3- Create php file in application->hook folder
7 - What is the default controller in CodeIgniter?
By default default controller is welcome, we change the default controller
Got application->config->routes.php file
we will see by default codeigniter show welcome
$route['default_controller'] = 'welcome';
here we can change our controller.
8 - List Databases supported By Codeigniter
9 - How can we load helper in form?
we can also load helper by application/config/autoload.php
$autoload['helpers'] = array('database', 'email', 'session');
10 - List of CodeIgniter Version
CodeIgniter 2 (legacy)
CodeIgniter 3 (current) - Recommended
CodeIgniter 4 (future)
11 - Codeigniter Feature
It is licensed under MIT so we can use free.
Light weight, all codeignier library,helper very small code so it is also fast.
Codeigniter generate SEO friendly URL.
Codeigniter follow MVC pattern, Means that spearates application logic and presentation parts.