Access PHP object from inside a function - php

Question

I have created a PHP class and I want to access its methods from a function in another file. Below is my code:
include_once PLUGIN_DIR_PATH."/classes/Brands.php";
function create_tables(){
$brand_obj = new Brands;
$brand_obj->create_brand_table();
}
function delete_tables() {
$brand_obj = new Brands;
$brand_obj->delete_brand_table();
}
Is it possible to create the object only once and then reuse it in every function? Right now, I am creating object in every function which is not a good practice.

Answer 1

You can use the global keyword to use a variable created outside a function inside a function:
global $object
code example :
include_once PLUGIN_DIR_PATH."/classes/Brands.php";
$brand_obj = new Brands;
function create_tables(){
global $brand_obj;
$brand_obj->create_brand_table();
}
function delete_tables() {
global $brand_obj;
$brand_obj->delete_brand_table();
}

Answer 2

I'm going to assume your actual functions do more than what you posted, otherwise you don't really need functions and can simply do this:
$brand_obj = new Brands;
$brand_obj->create_brand_table();
$brand_obj->delete_brand_table();
Otherwise, you can make a class and inject the Brands dependency into one of its properties via its constructor:
class TablesManager
{
private $brands;
public function __construct(Brands $brands)
{
$this->brands = $brands;
}
public function create_tables(): void
{
$this->brands->create_brand_table();
}
public function delete_tables(): void
{
$this->brands->delete_brand_table();
}
}
Usage:
$brands = new Brands();
$tables_manager = new TablesManager($brands);
$tables_manager->create_tables();
$tables_manager->delete_tables();
Note: calling a class SomethingManager is sometimes considered bad practice / a sign that the class does too many things. Consider (at least) giving it a more accurate name for your needs.
Demo: https://3v4l.org/iTmY6
Non-OOP alternative
function create_tables(Brands $brand_obj): void {
$brand_obj->create_brand_table();
}
function delete_tables(Brands $brand_obj): void {
$brand_obj->delete_brand_table();
}
$brand_obj = new Brands();
create_tables($brand_obj);
delete_tables($brand_obj);