C# 模式匹配比多态更好吗？

Question

C# 7 introduced pattern matching which allows, for example, to switch on types and act according to the underlying type.

Now, and based on the fact that C# is object-oriented the types that we switch on can, for example, implement a same base class or interface and override this base behaviour to achieve what pattern matching can do for us.

Why would I use pattern matching instead of this?

Answer 1

Pattern matching plays a central role in functional programming just as polymorphism plays a central role in object-oriented programming.

Besides that, I would personally use pattern matching whenever I know the full spectrum of possible types beforehand. Eg, a Maybe class which can either be a SomeValue or NoValue. For dynamic scenarios you can't use pattern matching in the first place.

To answer the original question: no, pattern matching is not better than polymorphism, it's something different.

Here is another great answer on the topic: https://softwareengineering.stackexchange.com/a/231095