Ruby object-oriented programming concept record

My memory has been poor and I need to take a look at it. Today I will look at Ruby's object-oriented programming content and write down some of these concepts for future reference.

Basic concepts:

I. Local variables, global variables, instance variables (object variables), and class variables.

II. Class Method and instance method (Object method ).

3. Inheritance.

4. Override method.

5. Reflection.

Sat. Encapsulation. (Public, private, protected ).

7. Polymorphism.

8. Nested class.

Module concept:

I. Module.

II. Namespace.

3. Mix-in)

Ruby object-oriented programming concept record