How to extend a class in C++?

Question

C++ / C#

Hello, there is such a task: "Extend the capabilities of the Dictionary class so that you can display the date of the last modification in the dictionary.". As I understand it, something was probably messed up in the task and you need to extend the list class, which is needed for lists, because I did not find the Dictionary class. If I'm still wrong, then how to extend the Dictionary class if one exists? Or if there is no such thing, then, accordingly, how to extend the list class?

PS: OOP started to pass recently, stupid questions are possible.

Answer 1

https://code-live.ru/post/cpp-class-inheritance/
this is called inheritance