Variables, Keywords, and Constants

Dim Statement in VB .Net

• The Dim statement is used in the variable declaration and storage/memory allocation for one or more variables.
• The Dim statement is used at the module, class, structure, procedure, or block level in the program.

Syntax for Variable Declaration in VB.Net :

Syntax: Variable_name[ ( [ boundslist ] ) ] [ As [ New ] datatype ] [ = initializer ]

Where,

• variablename – is the name of the variable.
• boundslist – optional. It provides a list of bounds of each dimension of an array variable.
• New – optional. It creates a new instance of the class when the Dim statement runs.
• datatype – Required. It specifies the data type of the variable.
• initializer: Optional if New is not specified. An expression that is evaluated and assigned to the variable when it is created.

Finally, In VB.NET, the declaration of a typical variable uses the following syntax:

Dim Variable_Name As Data_Type

Example:

• Dim StudentRollno As Integer
• Dim StudentName As String
• Dim Salary As Double
• Dim status As Boolean
• Dim dt As Date

• Dim num1, num2 As Integer

• Dim num1 As Integer
• Dim num2 As Integer

• Dim exitButton As New System.Windows.Forms.Button 

Variable Initialization in VB.Net

• Variables are initialized (assigned with a value) with an equal sign followed by a constant expression. The general form of initialization is:

Dim Variable_Name As Data_Type = Initialization_value(optional)

• For example –
  • Dim pi As Single = 3.14159
  • Dim CountryName As String = “India”