In this article we're going to explain how to check the version of the C# that your using.
Firstly, you have to check the .NET Framework version that is used in your project.
In Visual Studio you have to right-click on your project, and then go to the Properties.
There, you can check the Target Framework which is .NET Framework 3.1 in this example.
Now, let's check which C# version coresponds to that.
We can find the table at https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/language-versioning.
In this example, according to the table we're using C# 8.0.