Question

What is the difference between these two assignments? A inherits from Base.

Base b = new A();
A c = new A();

I don’t understand why this works, if the second is declared as type A.

List<Base> vals = new List<Base>();
values.Add(b);
values.Add(c);

What should I lookup to understand this more?

Answer 1

Inheritance constitutes an is a relation: if A inherits Base, it means that A can go wherever Base is allowed to go. This is precisely what your code snippet is showing: you can add an instance of A, a subclass of Base to a List<Base> where any subclass of Base can go.