Data Types & Keywords

C# Data Types

Data types define the type of data that a variable can store. The language supports various built-in data types, each with its own set of values and operations that can be performed on those values. Here are some of the common data types in C#:

Data Types	Size (in bits)	Range	Format Specifier
int	32	-2,147,483,648 to 2,147,483,647	{0}
long	64	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807	{0}
float	32	±1.5 x 10^−45 to ±3.4 x 10^38	{0:F}
double	64	±5.0 x 10^−324 to ±1.7 x 10^308	{0:F}
decimal	128	±1.0 x 10^-28 to ±7.9 x 10^28	{0:F}
char	16	Unicode characters	{0}
bool	8 (1 byte)	true or false	{0}
string		Sequence of characters	{0}
Additional data type information:
DateTime	64	January 1, 0001, through December 31, 9999 AD	{0:yyyy-MM-dd HH:mm:ss}
TimeSpan	64	-106751.99:02:48.4775808 to 106751.99:02:48.4775807	{0}
byte	8 (1 byte)	0 to 255	{0}
short	16	-32,768 to 32,767	{0}
ushort	16	0 to 65,535	{0}
sbyte	8 (1 byte)	-128 to 127	{0}
uint	32	0 to 4,294,967,295	{0}
ulong	64	0 to 18,446,744,073,709,551,615	{0}
float	32	±1.5 x 10^−45 to ±3.4 x 10^38	{0:F}
double	64	±5.0 x 10^−324 to ±1.7 x 10^308	{0:F}
decimal	128	±±1.0 x 10^-28 to ±7.9 x 10^28	{0:F}

This table includes the size of each C# data type in bits, the typical range of values they can represent, and the format specifiers commonly used with them. Format specifiers are placeholders used in string formatting to control the representation of values when outputting to the console or other output streams.

C# Keywords

A keyword is a reserved word that has a specific meaning and cannot be used as an identifier (such as the name of a variable, method, or class) in your code. These keywords are an integral part of the language's syntax and are used to define the structure and behavior of programs. Some common C# keywords include:

Types	Names
Access Modifiers:	public
	private
	protected
	internal
	protected internal
Modifiers:	static
	readonly
	const
	abstract
	sealed
Control Flow:	if
	else
	switch
	case
	default
	while
	do
	for
	foreach
	break
	continue
	return
Exception Handling:	try
	catch
	finally
	throw
Class & Object Keywords:	class
	struct
	interface
	enum
	object
	new
Others Keywords:	namespace
	using
	this
	base
	virtual
	override
	delegate
	event
	params
	as
	is

These are some of the essential data types and keywords in C#. There are additional keywords and data types available for more specialized scenarios and functionalities.

Escape Sequences

Escape sequences in C# are special sequences of characters that are used to represent certain non-printable characters or to achieve specific formatting in strings. These sequences are prefixed with a backslash ('\') and are followed by a character or a combination of characters. Escape sequences are often used in strings to include characters that would otherwise be difficult to represent directly.

Escape Sequence	Description
\n	Newline
\r	Carriage return
\t	Tab
\\	Backslash
\'	Single quote
\"	Double quote
\a	Alert (bell)
\b	Backspace
\f	Form feed
\v	Vertical tab
\0	Null character
\uXXXX	Unicode character (hex)
\xXX	Unicode character (hex)

These escape sequences are used within string literals to represent special characters or control characters in C# strings.