Visual Basic .NET
CSC 415 – Programming Languages
November 18, 2014
Mi Gyeong Gwak
HISTORY OF BASIC

BASIC (Beginner's All-purpose Symbolic Instruction Code)

John Kemeny and Thomas Kurtsz

Dartmouth College in 1964

General Electric 225

Interpreted BASIC
http://www.q7basic.org/History%20of%20BASIC.pdf
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general purpose
easy of use
expandable
Interactive
with debugging help
efficient
hardware independent
OS independent.
HISTORY OF VISUAL BASIC

Microsoft revived BASIC in 1991 (Visual Basic 1.0)

Visual Basic 6.0 in 1998

Object oriented

Event driven

Overcoming the limitations of being interpreted

Allowing programmers to generate a compiled executable code
http://www.max-visual-basic.com/history-of-visual-basic.html
NAMES

Begin with an alphabetical character or an underscore

Less than 1023 characters long

Case-insensitive

Reserved keywords


Escaped names are enclosed by brackets ([ ])
Unreserved keywords
SCOPES

BLOCK SCOPE

Do and Loop

For [Each] and Next

If and End If

Select and End Select

SyncLock and End SyncLock

Try and End Try

While and End While

With and End With
If n < 1291 Then
Dim cube As Integer
cube = n ^ 3
End If
SCOPES

Procedure scope

Module scope


Within modules, classes, structures

Private modifier
Namespace scope

Throughout the namespace

Friend or Public modifier
Private strMsg As String
Sub initializePrivateVariable()
strMsg = "This variable cannot be used outside this
module."
End Sub
Sub usePrivateVariable()
MsgBox(strMsg)
End Sub
DATA TYPES - Numeric

Integral Types

Non-integral Types

SByte (8-bit)

Decimal (128-bit fixed point)

Short (16-bit)

Single (32-bit floating point)

Integer (32-bit)

Double (64-bit floating point)

Long (64-bit)

Byte (8-bit)

UShort (16-bit)

UInteger (32-bit)

ULong (64-bit)
DATA TYPES – Character & Miscellaneous

Char

String

Boolean

Date

Object
DATA TYPES - Composite

Structures

Arrays

Classes

Constants

Enumerations
Dim airTemperatures(99, 99, 24) As Single
Dim twoSidedCube = {{{1, 2}, {3, 4}}, {{5, 6}, {7, 8}}}
OPERATORS
Dim lResult, rResult As Integer
Dim pattern As Integer = 12
' The low-order bits of pattern are 0000 1100.
lResult = pattern << 3
' A left shift of 3 bits produces a value of 96.
 Arithmetic operations
rResult = pattern >> 2
 Bit-shift operators (>> operator or << 'operator)
A right shift of 2 bits produces value of 3.

Comparison Operators

< > operator

Like operator

Is operator or IsNot operator

TypeOf Operator
testCheck = "F" Like "[A-Z]“
' The following statement returns True (does "F" occur in the set of
' characters from "A" through "Z"?)
OPERATORS


Concatenation operators

+ operator

& operator
Logical operators

Not operator

And operator

Or operator

Xor operator

AndAlso operator

OrElse operator
Dim a, b, c, d, e, f, g As Boolean
a = 23 > 14 And 11 > 8
b = 14 > 23 And 11 > 8
' The preceding statements set a to True and b to False.
c = 23 > 14 Or 8 > 11
d = 23 > 67 Or 8 > 11
' The preceding statements set c to True and d to False.
e = 23 > 67 Xor 11 > 8
f = 23 > 14 Xor 11 > 8
g = 14 > 23 Xor 8 > 11
' The preceding statements set e to True, f to False, and g to False.
CONTROL FLOW – Decision Structures

If…Then…Else construction

Select…Case construction

Try…Catch…Finally construction
Dim count As Integer = 0
Dim message As String
If count = 0 Then
message = "There are no items."
ElseIf count = 1 Then
message = "There is 1 item."
Else
message = "There are " & count & " items."
End If
CONTROL FLOW – Loop Structure

While…End While construction

Do…Loop construction

For…Next construction

For Each…Next construction
' Create a list of strings by using a
' collection initializer.
Dim lst As New List(Of String) _
From {"abc", "def", "ghi"}
' Iterate through the list.
For Each item As String In lst
Debug.Write(item & " ")
Next
Debug.WriteLine("")
'Output: abc def ghi
Support for Object Oriented
Programming

Abstraction

Encapsulation

Polymorphism

Inheritance
http://msdn.microsoft.com/en-us/library/aa289512(v=vs.71).aspx
CONCURRENCY EXCEPTIONS

DBConcurrencyException
Try
CustomersTableAdapter.Update(NorthwindDataSet)
Catch ex As DBConcurrencyException
Dim customErrorMessage As String
customErrorMessage = "Concurrency violation" & vbCrLf
customErrorMessage += CType(ex.Row.Item(0), String)
MessageBox.Show(customErrorMessage)
' Add business logic code to resolve the concurrency violation...
End Try
http://msdn.microsoft.com/en-US/library/y8fyz6xy(v=vs.80).aspx
EVENTS AND EVENT HANDLERS

Event keyword

RaiseEvent statement

WithEvents statement and Handles clause

AddHandler and RemoveHandler statements
Friend WithEvents Button1 As System.Windows.Forms.Button
Protected Sub Button1_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles Button1.Click
End Sub
http://msdn.microsoft.com/en-us/library/2z7x8ys3(v=vs.90).aspx
ERROR TYPES

Syntax errors

Run-time errors

Logic errors
DEMO

Visual Studio 2013
http://www.youtube.com/watch?v=DF2fCWLFSG0
READABILITY

English-like appearance

Keywords that control structures and data types are using a clear
language

Initial and terminal statements of control structures
KEYWORDS
AddHandler
Auto
CBool
AndAlso
ByVal
CDec
Double
End
Event
Implements
Integer
Like
Next
NotOverridable
Optional
RaiseEvent
RemoveHandler
Set
Then
AddressOf
Ansi
CByte
CDbl
CLng
Dim
Each
Enum
GoTo
Imports
Interface
MyClass
Not
Object
Property
ReadOnly
Resume
Structure
Throw
Alias
Case
CChar
Char
Declare
DirectCast
Else
WRITABILITY

Visual programming language

Integrated Development Environment (IDE) - Visual Studio

Control structure is intuitive

Correct termination for each initialization

Dim statement

Dim My_Counter As Integer
RELIABILITY

Integer overflow checking

Option Strict statement

Structured exception


Try…Catch…Finally control structure
Unstructured exception

On Error Go To statement

Resume statement

Error statement
COST

Microsoft Visual Studio 2013

Visual Studio Express Edition 2013

Migration from Visual Basic 6.0 to .NET

ArtinSoft’s Visual Basic Upgrade Companion

Great Migrations Studio

VB Migration Partner tool
CONCLUSION
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Visual Basic .NET