Keywords are reserved and cannot be used as identifiers. If you really want to choose a C# keyword as an identifier name, prefix it with a @.  For example, @new is a legal identifier but new is not.
 Highly discouraged by myself - there are lots of other words you can choose for your identifiers.
Table A.1 shows the list of C# keywords, and the chapters in which they are described in this book. Of all the C# keywords, only extern and stackalloc are beyond the scope of this book.
|abstract||Modifier – used to declare a class or class member as abstract||6|
|as||Operator – a convenient combination of the typeof and is operators||10|
|base||Used to invoke a constructor in the super(base)class ...|