What is the significance of a sealed partial class?

Question

In C#, what is the significance of a sealed partial class?

A Sealed class is a class that cannot be inherited.

A partial class is a class that can be split between 2 or more source files.

So why does a "sealed partial class have any significance?

Answer 1

A partial class is basically just syntactic sugar, you can define a class in two different files, in the same assembly. This is useful when part of your class is generated, for example using the Entity Framework DB first approach. It has nothing to do with inheritance.

A sealed class is a class that cannot be inherited. You would make a class sealed if inheriting from it could potentially break it, but you need it to be accessable outside of your own code.

There is no relation between the two keywords. A sealed partial class is simply a class, that might be defined in more files, and cannot be inherited from.

Answer 2

Partial class allows us to write a class across multiple files in a project. Partial indicates that the parts of the class can be defined in the namespace and all the parts must be used with the partial keyword. if any part is declared as sealed then the whole type is considered sealed.