Do I need to declare the db property in the class?

Question

PHP

There is a database class. Static singleton.
Is it necessary to create a db protected property when creating new classes and work with db-> inside the class, and not in DB::
If so, what is the fundamental difference?

Answer 1

There is a database class. Static singleton.

Singleton is not very good ... why - you can just google it, quite a few materials are devoted to this
Well, it all depends on how you will transfer the database object to a specific instance. If, for example, you use some kind of dependency injection, then by itself you need to write the base object into a class property. If you plan to do something like this $this->db = DB::getInstance() in classes, then this will give a special profit (except for a slight increase in code readability), but it will increase the amount of memory used (by allocating additional references to database object)