In this section, in the index controller, public function welcome(){return $this -> fetch('welcome'); }, the function name is consistent with the value of fetch(), and then in the newly created class library file, the function name has changed to index. I would like to know the reason for this. Thank you.

controller problem-PHP Chinese Network Q&A

In this section, in the index controller,

public function welcome(){return $this -> fetch('welcome'); }, the function name and the value of fetch() are Consistent, then in the newly created class library file, the function name changed to index. I would like to know the reason for this. Thank you