Why are const parameters not allowed in C#?

Question

It looks strange especially for C++ developers. In C++ we used to mark a parameter as `const` in order to be sure that its state will not be changed in the method. But why can't we mark as method parameters const in C#?

Answer 1

I believe const isn't supported in C# mainly due to compliance of CLS. The closest thing iirc to const in C# would be readonly, but there are minute differences. For Common Language Specifications info, check out this documentation by Microsoft.

https://docs.microsoft.com/en-us/dotnet/standard/language-independence-and-language-independent-components?redirectedfrom=MSDN

If you think of the bigger picture of languages who support const, C# will be of the few who do, and to change the standard of other languages because of C# is a bit biased in my opinion.

Thinking of C++, they've implemented the mutable keyword also in order to deal with observable consts. For me it wouldn't make sense to implement const-ness into C# and force it onto the rest of .NET where C++ has the ability to implement const and also mutable in order to counteract observable consts.

(At the end of the day I think this is more of a gray area topic, feel free to have your opinion of const/lack of const in C#)