When I use the "is" to check for null it works, but when I use "is not", I get this error: "Feature "not pattern" is not available in C#8.0. Please use language 9.0 or greater"
//check the image for my versions... my vs2019 is up to date, and I don't know where to change the version (if I needed to)
When I use the "is" to check for null it works, but when I use "is not", I get this error: "Feature "not pattern" is not available in C#8.0. Please use language 9.0 or greater"
//check the image for my versions... my vs2019 is up to date, and I don't know where to change the version (if I needed to)
dev-to-uploads.s3.amazonaws.com/up...