Vb.Net

Visual Basic .NET

:: Getting started :: Declaring variables :: Control Structures :: LINQ

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Chapter 1: Getting started

VB.NET Version	Visual Studio Version	.NET Framework Version	Release Date
7.0	2002	1.0	2002-02-13
7.1	2003	1.1	2003-04-24
8.0	2005	2.0 / 3.0	2005-10-18
9.0	2008	3.5	2007-11-19
10.0	2010	4.0	2010-04-12
11.0	2012	4.5	2012-08-15
12.0	2013	4.5.1 / 4.5.2	2013-10-17
14.0	2015	4.6.0 ~ 4.6.2	2015-07-20
15.0	2017	4.7	2017-03-07
16.0	2019	4.8	2019-04-18
16.9	2019	4.8	2020-02-19
17.0	2022	4.8	2022-11-08
17.1	2022	4.8	2023-02-21
17.2	2022	4.8	2023-05-23

Section 1.1: Hello World

First, install a version of Microsoft Visual Studio. Create a new Visual Basic Console Application project. The following code prints the string "Hello World" to the console.

Module Module1

    Sub Main()
        Console.WriteLine("Hello World")
    End Sub

End Module

Section 1.2: Hello World on a TextBox upon Clicking of a Button

In the designer, drag one TextBox and one Button onto the form. Double-click the button to create the click event handler, then add the line that sets the TextBox text.

Public Class Form1

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        TextBox1.Text = "Hello World"
    End Sub

End Class

Section 1.3: #Region

You can group related methods, events or properties using the #Region directive. Collapsing regions in the editor makes navigating large classes easier.

#Region "Events"

Protected Sub txtPrice_TextChanged(...) Handles txtPrice.TextChanged
    ' Do the ops here...
End Sub

Protected Sub txtTotal_TextChanged(...) Handles txtTotal.TextChanged
    ' Do the ops here...
End Sub

#End Region

Section 1.4: Creating a simple Calculator to get familiar with the interface and code

Build a basic Windows Forms calculator:

1. Install Visual Studio and start a new project.
2. Select Windows Forms Application from the Visual Basic templates.
3. Use the Toolbox to drag the controls you need (Buttons and a TextBox for display).
4. Double-click a button to create its click event and write logic that updates the TextBox.

Private Sub ButtonNumber_Click(sender As Object, e As EventArgs) _
    Handles Button0.Click, Button1.Click, Button2.Click

    Dim b = DirectCast(sender, Button)
    TextBoxDisplay.Text &= b.Text

End Sub

Private Sub ButtonEquals_Click(sender As Object, e As EventArgs) Handles ButtonEquals.Click
    Dim result = New DataTable().Compute(TextBoxDisplay.Text, "")
    TextBoxDisplay.Text = result.ToString()
End Sub

Chapter 2: Declaring variables

In Visual Basic .NET, variables are used to store and manipulate data. Before you can use a variable, you must declare it by specifying its name and the type of data it will hold.

The Dim Statement

The Dim (Dimension) statement is the most common way to declare a variable. It allocates memory for the variable and defines its characteristics.

The basic syntax is:

Dim variableName As DataType [= InitialValue]

Data Type	Description	Example Declaration
Integer	Stores whole numbers (no decimals)	Dim myNumber As Integer = 42
String	Stores a sequence of text/characters	Dim myText As String = "Hello"
Double	Stores high-precision floating-point numbers	Dim myPrice As Double = 19.99
Boolean	Stores true/false values	Dim isActive As Boolean = True
DateTime	Stores dates and times	Dim today As Date = #2026-05-22#

Code Examples

Here is how you can declare and assign variables inside a standard console application structure:

      Module Module1
    Sub Main()
        ' Declaring variables without an initial value
        Dim myNumber As Integer
        Dim myText As String
        
        ' Assigning values later in the code
        myNumber = 100
        myText = "Visual Basic Tutorial"
        
        ' Declaring and initializing a variable on a single line
        Dim itemsCount As Integer = 5
        
        ' Displaying variable values to the console
        Console.WriteLine(myText)
        Console.WriteLine("The number is: " & myNumber)
    End Sub
End Module
      

Key Rules for Naming Variables

1. Must begin with an alphabetic character or an underscore (_).
2. Cannot contain spaces or special characters (like %, &, $, @).
3. Cannot be a reserved VB.NET keyword (e.g., you cannot name a variable Dim or Sub).
4. Visual Basic is not case-sensitive, meaning myNumber and mynumber refer to the exact same variable.

Chapter 3: Control Structures

Placeholder for control structures.

Chapter 4: LINQ

Placeholder for LINQ.

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