Best way to pass function from MY_Controller to Controller

Since Welcome controller extends MY_Controller, the methods are available as part of the Welcome controller. Just call it like any other method.

In your example, it looks like you want to have the content_top() method overridden by the Welcome controller, so you would simply make a new method with the same name in the Welcome controller. You might look at making the content_top method an abstract method in MY_Controller, if all controllers should have that method.

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