C# Keywords


Keywords are predefined, reserved identifiersthat have special meanings to the compiler. They cannot be used as identifiersin
your program unless they include @ as a prefix.
For example, @if is a valid identifier but if is
not because if is a keyword.
Thefirst table in this topic lists keywords that are reserved identifiers in anypart of a C# program. The second table in this topic lists the contextualkeywords in C#. Contextual
keywords have special meaning only in a limitedprogram context and can be used as identifiers outside that context. Generally,as new keywords are added to the C# language, they are added as contextualkeywords in order 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	in (generic modifier)	int	interface
internal	is	lock	long
namespace	new	null	object
operator	out	out (generic modifier)	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

 
Contextual Keywords
 
A contextual keyword is used to provide a specific meaning in thecode, but it is not a reserved word in C#. Some contextual keywords, such as partial and where,
have specialmeanings in two or more contexts.

 

add	alias	ascending
async	await	descending
dynamic	from	get
global	group	into
join	let	orderby
partial (type)	partial (method)	remove
select	set	value
var	where (generic type constraint)	where (query clause)
yield