Information Technology Reference
In-Depth Information
Predefined Types
C# provides 15 predefined types, which are shown in Figure 3-4 and listed in Tables 3-1 and
3-2. They include 13 simple types and 2 non-simple types.
The names of all the predefined types consist of
all lowercase
characters. The predefined
simple types include the following:
11 numeric types, including
-
Various lengths of signed and unsigned integer types.
Floating point types—
float
and
double
.
-
A high-precision decimal type called
decimal
. Unlike
float
and
double
, type
decimal
can represent decimal fractional numbers exactly. It is often used for monetary
calculations.
-
A Unicode character type, called
char
.
A Boolean type, called
bool
. Type
bool
represents Boolean values and must be one of two
values—either
true
or
false
.
■
Note
Unlike C and C++, numeric values do not have a Boolean interpretation in C#.
The two non-simple types are the following:
Type
string
, which is a sequence of Unicode characters.
Type
object
, which is the type on which all other types are based.
Figure 3-4.
The predefined types
