Learning C# 3.0

Types

C# is a strongly typed language. That means that every object you create or use in a C# program must have a specific type. In other words, you must declare the object to be an integer or a string or a Dog or a Button. Essentially, the type indicates the characteristics of the object and what it can do.

Types come in two flavors: those that are built into the language (intrinsic types) and those you create yourself (classes and interfaces, discussed in Chapters Chapter 7 and Chapter 13). C# offers a number of intrinsic types, shown in Table 3-1.

Table 3-1. The intrinsic types built into C#

C# type	Size (in bytes)	.NET type	Description
byte	1	Byte	Unsigned (values between 0 and 255).
char	2	Char	Unicode characters (a modern way of storing most characters, including international language characters).
bool	1	Boolean	True or false.
sbyte	1	SByte	Signed (values between –128 and 127).
short	2	Int16	Signed (short) (values between –32,768 and 32,767).
ushort	2	UInt16	Unsigned (short) (values between 0 and 65,535).
int	4	Int32	Signed integer values between –2,147,483,648 and 2,147,483,647.
uint	4	UInt32	Unsigned integer values between 0 and 4,294,967,295.
float	4	Single	Floating-point number. Holds the values from approximately +/-1.5 x 10-45 to approximately +/-3.4 x 1038 with seven significant figures.
double	8	Double	Double-precision floating-point. Holds the values from approximately +/-5.0 x 10-324 to approximately +/-1.8 x 10308 with 15 to 16 significant figures.
decimal	12	Decimal	Fixed-precision up to 28 digits and the position ...