Appendix A. Keywords in C

Appendix A. Keywords in C#

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 @ . ^[1] For example, @new is a legal identifier but new is not.

^[1] 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.

Table A.1. C# keywords

Keyword	Comments	Chapter
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	7
bool	Simple type	9
break	Looping	11
byte	Simple type	9
case	Decision “ used together with switch	11
catch	Exception handling	13
char	Simple type	9
checked	Exception handling	13
class	Type “ used to declare a class type	6
const	Modifier “ used to declare a field as constant	8
continue	Looping	11
decimal	Simple type	9
default	Decision “ used together with switch and case	11
delegate	Modifier “ used to declare a delegate type	14
do	Looping	11
double	Simple type	9
else	Decision “ used together with if	11
enum	Type “ used to declare an enum type	25
event	Modifier “ used to declare an event instance	15
explicit	Modifier “ used to user-defined casts/conversions to declare that a user -defined cast is to be explicit	23
extern	Modifier “ to declare that a method implementation is in some external library	-
false	Value for boolean	9
finally	Exception handling	13
fixed	Used to mark a block of codes in a class which contains members which has pointer variables referencing them	29
float	Simple type	9
for	Looping	11
foreach	Looping	11
goto	Looping	11
if	Decision making	11
implicit	Modifier “ used to user-defined casts/conversions to declare that a user-defined cast is to be implicit	23
in	Looping “ used only together with foreach	11
int	Simple type	8
interface	Type “ used to declare an interface type	6
internal	Access modifier	8
is	Operator “ used to check if an object is of a particular type	6
lock	Marks a code block as a critical section	17
long	Simple type	9
namespace	Used to define a namespace	5
new	Used to create a new object or struct “ also used in name overriding	6/7/26
null	Literal for reference types	6
object	Alias for System.Object	6
operator	Modifier “ used to declare a method for operator overloading	22
out	Used to pass parameters by reference in methods	7
override	Modifier “ to declare a method as overriding a virtual one in a superclass	7
params	Type “ used to pass in a variable number of method parameters	7
private	Access modifier	8
protected	Access modifier	8
public	Access modifier	8
readonly	Modifier “ used to declare a field as read-only	8
ref	Used to pass parameters by reference in methods	7
return	To return from a method call	7
sbyte	Simple type	9
sealed	Modifier “ used to declare a class which cannot be subclassed, or method which cannot be overridden	6/7
short	Simple type	9
sizeof	Operator “ returns the size of a struct (including simple types) in number of bytes	10
stackalloc	Used in unsafe coding to allocate space on the stack manually	-
static	Modifier “ used to declare a class member as static	8/9
string	Alias for System.String	9
struct	Type “ used to declare a structure type	26
switch	Decision making	11
this	Represents the current object	6
throw	Exception handling	13
true	Value for boolean	9
try	Exception handling	13
typeof	Operator “ to return a System.Type instance representing the type of an object	10
uint	Simple type	9
ulong	Simple type	9
unchecked	Exception handling	13
unsafe	Modifier “ used to mark unsafe methods, classes, structs, class members, and an arbitrary block of code which contains pointer operations	29
ushort	Simple type	9
using	Used to import a namespace	5
virtual	Modifier “ to declare a method as overridable in a subclass	7
volatile	Modifier “ used to declare volatile fields	8
void	Return type for a method	7
while	Looping	11