String interpolation is supported by many programming languages including Python, Perl, PHP, Ruby, Java, Scala, etc. It was introduced in C# in C# 6.

The as operator in C# allows you to explicitly convert the result of an expression to a given reference type or a nullable value type. If the conversion isn’t possible, as returns null.

You can use the NET HELPMSG command to convert Windows error codes into strings or error messages. This guide shows how to do that.