How does the data get into the class?

Question

PHP

Another elementary question on the way of studying OOP, which is not directly discussed anywhere in practice (at least in an accessible language), namely, how does a class get its data for work?
That is, there is a certain class, it has several private variables - data that methods will work with, so far I have defined several ways how Data gets into the class:
1. Through the Constructor
2. Through setters
3. Directly after creating the class (if the variable public), like this: $class->value = 'Value';
...
How else?

Answer 1

1. Through the Constructor
2. Through setters
3. Directly after creating the class (if the variable is public), like this: $class->value = 'Value';
4. Load from external storage(AR)
5. via DTO

Answer 2

deserialization, __set_state

Answer 3

cloning

Answer 4

Reflection