In CodeIgniter 4, we can remap function calls with the use of the function in controller called _remap() method. The __remap() method will call every time that the controller is called even if a different function is used. Simply, we can say that remap() function will remap URI requests to specific controller methods. It’s double underscore before remap(). CodeIgniter will call the _remap() function before calling any other function. It’s pre defined method. Inside this article we will see the concept of __remap() function in CodeIgniter 4.