VB.Net - Constants and Enumerations

Module constantsNenum
   Sub Main()
      Const PI = 3.14149
      Dim radius, area As Single
      radius = 7
      area = PI * radius * radius
      Console.WriteLine("Area = " & Str(area))
      Console.ReadKey()
   End Sub
End Module

When the above code is compiled and executed, it produces the following result −

Area = 153.933

Print and Display Constants in VB.Net

VB.Net provides the following print and display constants −

Declaring Enumerations

An enumerated type is declared using the Enum statement. The Enum statement declares an enumeration and defines the values of its members. The Enum statement can be used at the module, class, structure, procedure, or block level.

The syntax for the Enum statement is as follows −

[ < attributepst > ] [ accessmodifier ]  [ Shadows ] 
Enum enumerationname [ As datatype ] 
   memberpst
End Enum

Where,

attributepst − refers to the pst of attributes appped to the variable. Optional.

accessmodifier − specifies which code can access these enumerations. Optional. Values can be either of the: Pubpc, Protected, Friend or Private.

Shadows − this makes the enumeration hide a programming element of identical name in a base class. Optional.

enumerationname − name of the enumeration. Required

datatype − specifies the data type of the enumeration and all its members.

memberpst − specifies the pst of member constants being declared in this statement. Required.

Each member in the memberpst has the following syntax and parts:

[< attribute pst >] member name [ = initiapzer ]

Where,

name − specifies the name of the member. Required.

initiapzer − value assigned to the enumeration member. Optional.

For example,

Enum Colors
   red = 1
   orange = 2
   yellow = 3
   green = 4
   azure = 5
   blue = 6
   violet = 7
End Enum

Example

The following example demonstrates declaration and use of the Enum variable Colors −

Module constantsNenum
   Enum Colors
      red = 1
      orange = 2
      yellow = 3
      green = 4
      azure = 5
      blue = 6
      violet = 7
   End Enum
   
   Sub Main()
      Console.WriteLine("The Color Red is : " & Colors.red)
      Console.WriteLine("The Color Yellow is : " & Colors.yellow)
      Console.WriteLine("The Color Blue is : " & Colors.blue)
      Console.WriteLine("The Color Green is : " & Colors.green)
      Console.ReadKey()
   End Sub
End Module

The Color Red is: 1
The Color Yellow is: 3
The Color Blue is: 6
The Color Green is: 4