Constants and Variables

Last revised 6/16/05 at 3:45pm

VB.NET Constants and Variables

A constant is a value that cannot be changed.

Examples of integer constants:
354, -37, 0, 246543 (no commas).
Examples of floating point constants:
4.642, -0.034, 5.98E+24 (mass of earth), 9.11E-31 (mass of electron)
Examples of string constants:
"A", "yes", "84835", "#$(&*^@#", " " (space), "" (zero length string).
A character can be stored in memory using its ASCII Code. ASCII means American System of Computer Information Interchange. Here is an ASCII Table of Printable Characters.
Actually, .NET uses the Unicode system for storing characters which includes the ASCII codes as a subset. For more information on Unicode, see this link: http://www.unicode.org.
Boolean constants:
True, False

A VB.NET variable
Underscore characters are not recommended in variable names.
The length restriction of 1023 for a variable name also applies to fully qualified names.
Although VB is case insensitive, two styles of capitalization are preferred:

Dim x, y, selectedIndex As Integer

Dim name As String

Dim flag As Boolean

Dim maxVal, massInKilos As Double

Dim a As String = "peach"

Dim flag As Boolean = True

Dim maxVal As Double = 35.875

Dim x = 2, y As Integer = 3

Dim x As Double= 2.35, y As Integer = 4