Question

I have a class with own methods and on the other side a php file what contains external methods. From documentation is clear that inside of a class includeing external functions is not possible

How could I inculde this functions in my class. Making an another class and extend my first class it can not be an option.

Answer 1

You can call external functions from a class, even if they are not enclosed in a class of their own:

Global.php

<?php
function doSomething() {
    return 'Hello';
}
?>

ExampleClass.php

<?php
include_once('Global.php');

class ExampleClass
{
    public function example() {
        return doSomething();
    }
}
?>

Although you probably wouldn’t have the include in the actual class file.