Class declaration and instantiation techniques

Knowledge of class attributes and class constants

Class automatic loading technology

Access restriction and encapsulation technology of class members

Class inheritance and code reuse

Detailed explanation of the use of range parsing operator (::)

Detailed explanation of static keyword

Late static binding technology

Overloading techniques for attributes and methods in classes

Detailed explanation of Trait characteristic technology

First introduction to namespaces

How to declare multiple namespaces in one script

How to import an external namespace