System.Object being the base class

Question

This question may be usual for many, i tried for an hour to understand the things but getting no proper explanation.

MSDN says, System.Object is the ultimate base class of all classes in the .NET Framework; it is the root of the type hierarchy.

When C# doesn't allow multiple inheritance, how can I inherit, say a Class A to Class B. ? Because all classes, already inherits from System.Object right? Here I am talking about the normal inheritance.

Class A { --- }
Class B : A { --- }

Please, clear my doubts. Thank you.

Update:

Again, My doubt is about, All classes inheriting from System.Object, then that would make Class B having Class A as well as System.Object. From my above example

Answer 1

Correct, C# only allows single inheritence. The System.Object class is inherited implicitly by your Class A. So Class B is-a A, which is-a System.Object. This is taken care of by the compiler so you don't need to explicitly say that Class A : System.Object (though you can if you want).

Answer 2

Very easy. Ape inherits from animal, chimpanzee inherits from ape. Chimpanzee inherits from animal too, but not primarily, only through ape. In .NET, if class does not state its inheritance explicitly, the compiler adds IL code to inherit it from System.Object. If it does, it inherits System.Object through parent types.

Answer 3

Look, you can only have one father. But your father also can have a father. Thus, you inherit some attributes from your grandfather. Dog class inherits from Mammals, which in turn inherits from Animal class, which in turn inherits from LivingThing class.