Identifying Keywords The C# language reserves 77 identifiers for its own use, and you should not reuse these identifiers for your own purposes. These identifiers are called keywords, and each has a particular meaning. Examples of keywords are class, namespace, and using. You'll learn the meaning of most of the keywords as you proceed through this book. The keywords are listed in the following table. abstract as base bool break byte case catch char checked class const continue decimal default delegate do double else enum event explicit extern false finally fixed float for foreach goto if implicit in int interface internal is lock long namespace new null object operator out override params private protected public readonly ref return sbyte sealed short sizeof stackalloc static string struct switch this throw true try typeof uint ulong unchecked unsafe ushort using virtual void volatile while TIP In the Visual Studio 2005 Code and Text Editor window, keywords are colored blue when you type them. . called keywords, and each has a particular meaning. Examples of keywords are class, namespace, and using. You'll learn the meaning of most of the keywords. Identifying Keywords The C# language reserves 77 identifiers for its own use, and