Data types refer to an extensive system used for declaring variables or functions of different types.
The type of a variable determines how much space it occupies in storage and how the bit pattern stored is interpreted.
Data Types Available in VB.Net
VB.Net provides a wide range of data types. The following table shows all the data types available:
Data Type | Storage Allocation | Value Range |
Boolean | Depends on implementing platform | True or False |
Byte | 1 byte | 0 through 255 (unsigned) |
Char | 2 bytes | 0 through 65535 (unsigned) |
Date | 8 bytes | 0:00:00 (midnight) on January 1, 0001 through 11:59:59 PM on December 31, 9999 |
Decimal | 16 bytes | 0 through +/-79,228,162,514,264,337,593,543,950,335 (+/-7.9...E+28)with no decimal point; 0 through +/-7.9228162514264337593543950335 with 28 places to the right of the decimal |
Double | 8 bytes | -1.79769313486231570E+308 through -4.94065645841246544E-324, for negative values 4.94065645841246544E-324 through 1.79769313486231570E+308, for positive values
|
Integer | 4 bytes | -2,147,483,648 through 2,147,483,647 (signed) |
Long | 8 bytes | -9,223,372,036,854,775,808 through 9,223,372,036,854,775,807(signed) |
Object | 4 bytes on 32-bit platform
8 bytes on 64-bit platform
| Any type can be stored in a variable of type Object |
SByte | 1 byte | -128 through 127 (signed) |
Short | 2 bytes | -32,768 through 32,767 (signed) |
Single | 4 bytes | -3.4028235E+38 through -1.401298E-45 for negative values; 1.401298E-45 through 3.4028235E+38 for positive values |
String | Depends on implementing platform | 0 to approximately 2 billion Unicode characters |
UInteger | 4 bytes | 0 through 4,294,967,295 (unsigned) |
ULong | 8 bytes | 0 through 18,446,744,073,709,551,615 (unsigned) |
User-Defined | Depends on implementing platform | Each member of the structure has a range determined by its data type and independent of the ranges of the other members |
UShort | 2 bytes | 0 through 65,535 (unsigned) |
Example
The following example demonstrates use of some of the types:
Module DataTypes
Sub Main()
Dim b As Byte
Dim n As Integer
Dim si As Single
Dim d As Double
Dim da As Date
Dim c As Char
Dim s As String
Dim bl As Boolean
b = 1
n = 1234567
si = 0.12345678901234566
d = 0.12345678901234566
da = Today
c = "U"c
s = "Me"
If ScriptEngine = "VB" Then
bl = True
Else
bl = False
End If
If bl Then
'the oath taking
Console.Write(c & " and," & s & vbCrLf)
Console.WriteLine("declaring on the day of: {0}", da)
Console.WriteLine("We will learn VB.Net seriously")
Console.WriteLine("Lets see what happens to the floating point variables:")
Console.WriteLine("The Single: {0}, The Double: {1}", si, d)
End If
Console.ReadKey()
End Sub
End Module
When the above code is compiled and executed, it produces following result:
U and, Me
declaring on the day of: 12/4/2012 12:00:00 PM
We will learn VB.Net seriously
Lets see what happens to the floating point variables:
The Single:0.1234568, The Double: 0.123456789012346
The Type Conversion Functions in VB.Net
VB.Net provides the following inline type conversion functions:
S.N | Functionss & Description |
1 | CBool(expression) Converts the expression to Boolean data type. |
2 | CByte(expression) Converts the expression to Byte data type. |
3 | CChar(expression) Converts the expression to Char data type. |
4 | CDate(expression) Converts the expression to Date data type |
5 | CDbl(expression) Converts the expression to Double data type. |
6 | CDec(expression) Converts the expression to Decimal data type. |
7 | CInt(expression) Converts the expression to Integer data type. |
8 | CLng(expression) Converts the expression to Long data type. |
9 | CObj(expression) Converts the expression to Object type. |
10 | CSByte(expression) Converts the expression to SByte data type. |
11 | CShort(expression) Converts the expression to Short data type. |
12 | CSng(expression) Converts the expression to Single data type. |
13 | CStr(expression) Converts the expression to String data type. |
14 | CUInt(expression) Converts the expression to UInt data type. |
15 | CULng(expression) Converts the expression to ULng data type. |
16 | CUShort(expression) Converts the expression to UShort data type. |
Example:
The following example demonstrates some of these functions:
Module DataTypes
Sub Main()
Dim n As Integer
Dim da As Date
Dim bl As Boolean = True
n = 1234567
da = Today
Console.WriteLine(bl)
Console.WriteLine(CSByte(bl))
Console.WriteLine(CStr(bl))
Console.WriteLine(CStr(da))
Console.WriteLine(CChar(CChar(CStr(n))))
Console.WriteLine(CChar(CStr(da)))
Console.ReadKey()
End Sub
End Module
When the above code is compiled and executed, it produces following result:
True
-1
True
12/4/2012
1
1