Microsoft Visual Basic

Implementation of programming language Basic

Visual Basic is an IDE created by Microsoft Corporation. It was a part of Visual Studio till 1998 (version 6), and was replaced with Microsoft Visual Basic .NET later.

Examples:

Hello, World!:

Example for versions Microsoft Visual Basic 6

The intended use of Visual Basic is GUI applications development, so creating a simple console application is a non-trivial task itself. This example features:

importing required functions from standard library;
console creation;
getting the handle of console output stream;
writing the message to this stream and
deallocation of used objects.

Option Explicit
 Declare Function AllocConsole Lib "kernel32" () As Long
 Declare Function FreeConsole Lib "kernel32" () As Long
 Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long
 Declare Function GetStdHandle Lib "kernel32" (ByVal nStdHandle As Long) As Long
 Declare Function WriteConsole Lib "kernel32" Alias "WriteConsoleA" _
 (ByVal hConsoleOutput As Long, lpBuffer As Any, ByVal _
 nNumberOfCharsToWrite As Long, lpNumberOfCharsWritten As Long, _
 lpReserved As Any) As Long
 Declare Function Sleep Lib "kernel32" (ByVal dwMilliseconds As Long) As Long
Private Sub Main()
 'create a console instance
 AllocConsole
 'get handle of console output
 Dim hOut As Long
 hOut = GetStdHandle(-11&)
 'output string to console output
 Dim s As String
 s = "Hello, World!" & vbCrLf
 WriteConsole hOut, ByVal s, Len(s), vbNull, vbNull
 'make a pause to look at the output
 Sleep 2000
 'close the handle and destroy the console
 CloseHandle hOut
 FreeConsole
End Sub

Factorial:

Example for versions Microsoft Visual Basic 6

This example uses iterative factorial definition. Trying to calculate 13! produces an arithmetic overflow error, so program output ends with line “12! = 479001600”. After this a message “Run-time error ‘6’: Overflow” pops up.

Option Explicit
 Declare Function AllocConsole Lib "kernel32" () As Long
 Declare Function FreeConsole Lib "kernel32" () As Long
 Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long
 Declare Function GetStdHandle Lib "kernel32" (ByVal nStdHandle As Long) As Long
 Declare Function WriteConsole Lib "kernel32" Alias "WriteConsoleA" _
 (ByVal hConsoleOutput As Long, lpBuffer As Any, ByVal _
 nNumberOfCharsToWrite As Long, lpNumberOfCharsWritten As Long, _
 lpReserved As Any) As Long
 Declare Function Sleep Lib "kernel32" (ByVal dwMilliseconds As Long) As Long
Private Sub Main()
 'create a console instance
 AllocConsole
 'get handle of console output
 Dim hOut As Long
 hOut = GetStdHandle(-11&)
 'output string to console output
 Dim s As String
 Dim i As Integer
 Dim f As Long
 f = 1
 s = "0! = 1" & vbCrLf
 WriteConsole hOut, ByVal s, Len(s), vbNull, vbNull
 For i = 1 To 16 Step 1
 f = f * i
 s = i & "! = " & f & vbCrLf
 WriteConsole hOut, ByVal s, Len(s), vbNull, vbNull
 Next i
 'make a pause to look at the output
 Sleep 2000
 'close the handle and destroy the console
 CloseHandle hOut
 FreeConsole
End Sub

Fibonacci numbers:

Example for versions Microsoft Visual Basic 6

This example uses recursive definition of Fibonacci numbers.

Option Explicit
 Declare Function AllocConsole Lib "kernel32" () As Long
 Declare Function FreeConsole Lib "kernel32" () As Long
 Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long
 Declare Function GetStdHandle Lib "kernel32" (ByVal nStdHandle As Long) As Long
 Declare Function WriteConsole Lib "kernel32" Alias "WriteConsoleA" _
 (ByVal hConsoleOutput As Long, lpBuffer As Any, ByVal _
 nNumberOfCharsToWrite As Long, lpNumberOfCharsWritten As Long, _
 lpReserved As Any) As Long
 Declare Function Sleep Lib "kernel32" (ByVal dwMilliseconds As Long) As Long
Public Function Fibonacci(ByVal n As Integer) As Integer
 If (n <= 2) Then
 Fibonacci = 1
 Else
 Fibonacci = Fibonacci(n - 1) + Fibonacci(n - 2)
 End If
End Function
Private Sub Main()
 'create a console instance
 AllocConsole
 'get handle of console output
 Dim hOut As Long
 hOut = GetStdHandle(-11&)
 'output string to console output
 Dim s As String
 Dim i As Integer
 For i = 1 To 16 Step 1
 s = Fibonacci(i) & ", "
 WriteConsole hOut, ByVal s, Len(s), vbNull, vbNull
 Next i
 s = "..." & vbCrLf
 WriteConsole hOut, ByVal s, Len(s), vbNull, vbNull
 'make a pause to look at the output
 Sleep 2000
 'close the handle and destroy the console
 CloseHandle hOut
 FreeConsole
End Sub

Microsoft Visual Basic

Examples:

Hello, World!:

Factorial:

Fibonacci numbers:

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