Public Class Form1

    '--Subroutine for a Click event occurring on the Add Button. 
    '--Do not try and code the start and end code of the Subroutine, let Visual 
    '--Basic Do it for you by double clicking on the Add Button on the Form while
    '--in VB Designer View. 

    Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click

        '--Dimension variables as "Double:" rather than "Integer" so that both 
        '--Whole Numbers and Decimals can be processed. 
        Dim dblFirstNumber As Double
        Dim dblSecondNumber As Double
        Dim dblSumOfNumbers As Double

        '--Use Val function to convert first textbox Number to Number Format
        '--The Val function is friendlier and does not crash the program with blanks
        '--or other Non-Numeric values like the words "one", "two" etc 
        '--If the Data is not Numeric is just sets the value to Zero. 
        dblFirstNumber = Val(txt1stNumber.Text)

        '--Use the Cast as Double CDbl function to convert the second textbox Number
        '--into a "Double" numeric format that caters for both whole numbers and Decimals.
            dblSecondNumber = CDbl(txt2ndNumber.Text)

        '--Add up the Two Numbers
        dblSumOfNumbers = dblFirstNumber + dblSecondNumber

        '--Move the Sum Answer into the Label on the Form so it can be displayed.   
        lblAnswer.Text = dblSumOfNumbers

    End Sub

    Private Sub btnClear_Click(sender As Object, e As EventArgs) Handles btnClear.Click
        '--Clear out all values in Input Text Boxes and the Output Results Label 
        txt1stNumber.Text = Nothing
        txt2ndNumber.Text = Nothing
        lblAnswer.Text = Nothing

    End Sub
End Class
by

Visual basic (VB.net) Online Compiler

Write, Run & Share VB.net code online using OneCompiler's VB.net online compiler for free. It's one of the robust, feature-rich online compilers for VB.net language, running on the latest version 16. Getting started with the OneCompiler's VB.net compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as VB.net. OneCompiler also has reference programs, where you can look for the sample code to get started with.

Read input from STDIN in VB.net

OneCompiler's VB.net online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample VB.net program which takes name as input and prints hello message with your name.

Public Module Program
	Public Sub Main(args() As string)
	 Dim name as String = Console.ReadLine()    ' Reading input from STDIN
   Console.WriteLine("Hello " & name)           ' Writing output to STDOUT
	End Sub
End Module

About VB.net

Visual Basic is a event driven programming language by Microsoft, first released in the year 1991.

Key Features

  • Beginner's friendly language.
  • Simple and object oriented programming language.
  • User friendly language and easy to develop GUI based applications.

Syntax help

Variables

Variable is a name given to the storage area in order to identify them in our programs.

Simple syntax of Variable declaration is as follows

Dim variableName [ As [ New ] dataType ] [ = initializer ]

Variable initialization

variableName = value

Conditional Statements

1. If

If condition-expression Then 
    'code
End If

2. If-else

If(conditional-expression)Then
   'code if the conditional-expression is true 
Else
  'code if the conditional-expression is false 
End If

3. If-else-if ladder

If(conditional-expression)Then
   'code if the above conditional-expression is true 
Else If(conditional-expression) Then
        'code if the above conditional-expression is true 
    Else
        'code if the above conditional-expression is false 
End If

4. Nested-If

If(conditional-expression)Then
   'code if the above conditional-expression is true
   If(conditional-expression)Then
         'code if the above conditional-expression is true 
   End If
End If

5. Select Case

Select [ Case ] expression
   [ Case expressionlist
      'code ]
   [ Case Else
      'code ]
End Select

Loops

1. For..Next

For counter [ As datatype ] = begin To end [ Step step ]
   'code
   [ Continue For ]
   'code
   [ Exit For ]
   'code
Next [ counter ]

2. For..Each

For Each element [ As datatype ] In group
   'code
   [ Continue For ]
   'code
   [ Exit For ]
   'code
Next [ element ]

3. While

While conditional-expression
   'Code 
   [ Continue While ]
   'Code
   [ Exit While ]
   'Code
End While

4. Do-while

Do { While | Until } conditional-expression
   'Code
   [ Continue Do ]
   'Code
   [ Exit Do ]
   'Code
Loop

Do
   'Code
   [ Continue Do ]
   'Code
   [ Exit Do ]
   'Code
Loop { While | Until } conditional-expression

Procedures

Procedure is a sub-routine which contains set of statements. Usually Procedures are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

Procedures are of two types.

1. Functions

Functions return a value when they are called.

[accessModifiers] Function functionName [(parameterList)] As returnType
   'code
End Function

2. Sub-Procedures

Sub-procedures are similar to functions but they don't return any value.

Sub ProcedureName (parameterList)
'Code
End Sub