How to check the version of CodeIgniter framework ?

CodeIgniter is a powerful PHP framework used to create and design projects. The functionality and method calls are dependent on the CodeIgniter framework. The methods get deprecated based on the version of PHP and some of the functionality is specific to the browser. Therefore, it is important to check the version of CodeIgniter framework, which is possible using the following two methods : 

Using system/core/CodeIgniter.php: The CodeIgniter framework provides a well structured framework to visualize the values for constants and sessions stored. It contains a directory within it named system folder which contains core database files like cache, driver, query builder etc. Within this folder is the core folder which contains the base class of your application. The version of CodeIgniter framework can be accessed using this file which has the version stored in the constant named CI_VERSION. The below screenshot indicates this: 

Example: The below screenshot indicates that the version in use is 3.1.11. 

Using php echo command: CI_VERSION is build in constant in CodeIgniter framework, which contains value of version of the framework that is currently being used. This displays the CodeIgniter framework version in which the project is being run on. 

Example:

Output:

3.1.11