Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
Keywords are predefined, reserved identifiers that have special meanings to the compiler. You can't use them as identifiers in your program unless you prefix them with @. For example, @if is a valid identifier, but if isn't because if is a keyword.
The C# language reference documents the most recently released version of the C# language. It also contains initial documentation for features in public previews for the upcoming language release.
The documentation identifies any feature first introduced in the last three versions of the language or in current public previews.
Tip
To find when a feature was first introduced in C#, consult the article on the C# language version history.
The first table in this article lists keywords that are reserved identifiers in any part of a C# program. The second table lists the contextual keywords in C#. Contextual keywords have special meaning only in a limited program context and can be used as identifiers outside that context. Generally, as new keywords are added to the C# language, they're added as contextual keywords to avoid breaking programs written in earlier versions.
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
Contextual keywords
A contextual keyword provides a specific meaning in the code, but it isn't a reserved word in C#. Some contextual keywords, such as partial and where, have special meanings in two or more contexts.
Collaborate with us on GitHub
The source for this content can be found on GitHub, where you can also create and review issues and pull requests. For more information, see our contributor guide.
