require_once() in a class

Question

I noticed that if I declare a function inside a class method that has the same name as a outside function I get a error:

function a(){
  ...
}

class foo{
  public function init(){
    function a(){  // <- error
    ...    
    }
    ...
  }

}

this however would work:

function a(){
  ...
}

class foo{
  public static function a(){
    ...
  }
}

Can I include a set of functions that act as static methods for this class using require_once or something like that?

require_once('file.php'); after class foo{ doesn't work...

Answer 1

PHP allows to nest function declarations in others, but it doesn't actually have nested functions. They always end up in the global scope. So the a() that you define in your init method clashes with the already defined function a().

The static function a() is associated with the class namespace, even if it behaves like a function, not a method.

Invoking a require_once statement in a class definition is not possible. The PHP syntax does not allow for it. Class definitions are special scopes / language constructs, that only allow function or variable declarations within the immediate parsing level. - So PHP does not allow for that (classes and their methods must be declared at once, not assembled), and there are no really nice or advisable workarounds for what you want.