How to represent the hierarchy of elements?

Question

C++ / C#

What is the best way to represent a set of objects (of different types) that
are nested inside each other? Can move to a higher level of the hierarchy, collapse
by certain properties, filter ...

Answer 1

class Obj { }
class Collection : Obj
{
   private List<Obj> items;
}
class Item : Obj { }

the pattern is called Linker. You can start with Wikipedia .

Answer 2

it is not entirely clear what is meant by "different types", usually a hierarchy of elements is not built from anything, the simplest case is a class of the form

class Item{
public Item Parent;
public Object Data;
public List<Item> Childs;
}

Accordingly, Parent stores information about the parent, Data "any type", and Childs, respectively, the list of children