Category: OOP

Use static members for class-level state and utilities (carefully).

Define immutable class-level values with const.

Learn common inheritance structures: single, multilevel, hierarchical, and multiple.

Extend one parent class — the standard inheritance model in PHP.

Build inheritance chains where a child becomes a parent for another class.

Create multiple specialized subclasses from one shared base class.

Understand multiple inheritance and how PHP approximates it with interfaces and traits.

Call the same method name on different objects and get type-specific behavior.

Learn overloading concepts and PHP’s practical alternatives.

Hide internal state and expose controlled operations through methods.