Error Handling

Hi to all developers...
In CI documentation, I've read what I must do for error handling when finishing app development. And also I've design a custom 404 error page for a better and user friendly view.

My question is: In final product, the users should not see PHP or Databases errors... but what about general errors? How could I handle those and create a better custom page for them?

suppose some users enter some disallowed characters in address bar, or a form CSRF time finished or something like these, then the users a bad error page with some messages like these:

An Error Was Encountered
The URI you submitted has disallowed characters.

thanks a lot.

In Codeigniter 3.X you have extra folder in views called "errors", you can all type of errors view from there to make it user friendly

In Codeigniter 3.X you have extra folder in views called "errors", you can all type of errors view from there to make it user friendly

Thanks. But I know about these folders too!

I mean, for 404 error page, I could create a controller and a method, and route to this method via $route['404_override']. In this way, I could have a page like other pages, with their theme, but for errors. How could these about general errors?