Appendix C. Common Data Types
Each of the .NET
languages can provide its own keywords for the types it supports. For
example, a keyword for an integer in VB is
Integer, whereas in C# or C++ it is
int; a boolean is Boolean in
VB, but bool in C# or C++. In any case, the
integer is mapped to the class Int32, and the boolean is mapped to
the class Boolean in the System namespace. Table C-1 lists all simple
data types common to the .NET Framework. Non-CLS-compliant types are
not guaranteed to interoperate with all CLS-compliant languages.
Table C-1. Common data types|
|
Boolean
|
True or false.
| |
Byte
|
8-bit unsigned integer: 0 to 255.
| |
Char
|
Character. Unicode 16-bit character.
| |
DateTime
|
Represents a date and time value.
| |
Decimal
|
Can represent positive and negative values with 28 significant
digits: -79,228,162,514,264,337,593,543,950,335 to
79,228,162,514,264,337,593,543,950,335 .
| |
Double
|
Stores 64-bit floating-point values: -1.79769313486231570e308 to
1.79769313486231570e308.
| |
Guid
|
Represents a globally unique identifier (GUID); this is stored
internally as a 128-bit integer. Commonly represented as a series of
lowercase hexadecimal digits in groups of 8, 4, 4, 4, and 12 digits
and separated by hyphens (e.g.,
382c74c3-721d-4f34-80e5-57657b6cbc27).
| |
Int16
|
Stores 16-bit signed integers: -32,768 to 32,767.
| |
Int32
|
Stores 32-bit signed integers: -2,147,483,648 to 2,147,483,647.
| |
Int64
|
Stores 64-bit signed integers: -9,223,372,036,854,775,808 to
9,223,372,036,854,775,807.
| |
SByte
|
Represents an 8-bit signed integer. The SByte type is not
CLS-compliant. -128 to 127.
| |
Single
|
Represents an IEEE 754f, single precision, 32-bit value:
-3.40282346638528859e38 to 3.40282346638528859e38.
| |
String
|
Represents a string of Unicode characters.
| |
UInt16
|
Represents a 16-bit unsigned integer. The UInt16 type is not CLS-
compliant. 0 to 65,535.
| |
UInt32
|
Represents a 32-bit unsigned integer. The UInt32 type is not CLS-
compliant. 0 to 4,294,967,295
| |
UInt64
|
Represents a 64-bit unsigned integer. The UInt64 type is not CLS-
compliant. The UInt64 data type can represent positive integers with
18 significant digits: 0 to 184,467,440,737,095,551,615.
| |
Void
|
Void.
|
Table C-2 shows a number of useful container types
that the .NET Framework provides.
Table C-2. Container types|
|
Array
|
General array construct.
| |
ArrayList
|
This class
implements the IList interface. The array can grow or shrink
dynamically in size.
| |
BitArray
|
This class represents a compact array of bit values. Each element
represents a Boolean value (true/false).
| |
HashTable
|
This class represents a collection of associated keys and values that
are organized based on the hash code of the key.
| |
Queue
|
This class represents a first-in, first-out collection construct.
| |
SortedList
|
This class is similar to HashTable except that all elements are
sorted by their actual keys (not hashed) and elements are accessible
through either key or index.
| |
Stack
|
This class represents a first-in, last-out stack construct.
|
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