VBScript Basics
VBScript stands for Visual Basic Scripting that forms a
subset of Visual Basic for Applications (VBA). VBA is a
product of Microsoft which is included NOT only in other
Microsoft products such as MS Project and MS Office but
also in Third Party tools such as AUTO CAD.
Features of VBScript
• VBScript is a lightweight scripting language, which has
a lightning fast interpreter.
• VBScript, for the most part, is case insensitive. It has
a very simple syntax, easy to learn and to implement.
• Unlike C++ or Java, VBScript is an object-based scripting
language and NOT an Object-Oriented Programming language.
• It uses Component Object Model (COM) in order to access
the elements of the environment in which it is executing.
• Successful execution of VBScript can happen only if it is
executed in Host Environment such as Internet Explorer (IE),
Internet Information Services (IIS) and Windows Scripting Host (WSH)
VBScript – Version History and Uses
VBScript was introduced by Microsoft way back in 1996 and its
first version was 1.0. The current stable version of VBScript
is 5.8, which is available as part of IE8 or Windows 7.
The VBScript usage areas are aplenty and not restricted to the below list.
• VBScript is used as a scripting language in one of the
popular Automation testing tools – Quick Test Professional abbreviated as QTP.
• Windows Scripting Host, which is used mostly by Windows
System administrators for automating the Windows Desktop.
• Active Server Pages (ASP), a server side scripting
environment for creating dynamic webpages which uses VBScript or Java Script.
• VBScript is used for Client side scripting in Microsoft Internet Explorer.
• Microsoft Outlook Forms usually runs on VBScript; however,
the application level programming relies on VBA (Outlook 2000 onwards).
Disadvantages
1. OVERVIEW
• VBScript is used only by IE Browsers. Other browsers such as
Chrome, Firefox DONOT Support VBScript. Hence, JavaScript is preferred over VBScript.
• Since there is no development environment available by default, debugging is difficult.
• VBScript has a Limited command line support
Where VBScript is Today?
The current version of VBScript is 5.8, and with the recent
development of .NET framework, Microsoft has decided to
provide future support of VBScript within ASP.NET for web
development. Hence, there will NOT be any more new versions
of VBScript engine but the entire defect fixes and security
issues are being addressed by the Microsoft sustaining
Engineering Team. However, VBScript engine would be shipped
as part of all Microsoft Windows and IIS by default.
2. SYNTAX
Your First VBScript
Let us write a VBScript to print out "Hello World".
In the above example, we called a function document.write,
which writes a string into the HTML document. This function
can be used to write text, HTML, or both. So, the above
code will display the following result:
Hello World!
Whitespace and Line Breaks
VBScript ignores spaces, tabs, and newlines that appear
within VBScript programs. One can use spaces, tabs, and
newlines freely within the program, so you are free to
ormat and indent your programs in a neat and consistent way
that makes the code easy to read and understand.
Formatting
VBScript is based on Microsoft's Visual Basic. Unlike JavaScript,
no statement terminators such as semicolon is used to terminate
a particular statement.
Single Line Syntax
Colons are used when two or more lines of VBScript ought to
be written in a single line. Hence, in VBScript, Colons act
as a line separator.
Multiple Line Syntax
When a statement in VBScript is lengthy and if user wishes to
break it into multiple lines, then the user has to use
underscore "_". This improves the readability of the code.
The following example illustrates how to work with multiple lines.
Reserved Words
The following list shows the reserved words in VBScript.
These reserved words SHOULD NOT be used as a constant or
variable or any other identifier names.
And As Boolean
ByRef Byte ByVal
Call Case Class
Const Currency Debug
Dim Do Double
Each Else ElseIf
Empty End EndIf
Enum Eqv Event
Exit False For
Function Get GoTo
If Imp Implements
In Integer Is
Let Like Long
TypeOf Until Variant
Wend While With
Xor Eval Execute
Msgbox Erase ExecuteGlobal
Option Explicit Randomize SendKeys
Case Sensitivity
VBScript is a case-insensitive language. This means that
language keywords, variables, function names and any other
identifiers need NOT be typed with a consistent
capitalization of letters. So identifiers int_counter,
INT_Counter and INT_COUNTER have the same meaning within VBScript.
Comments in VBScript
Comments are used to document the program logic and the user
information with which other programmers can seamlessly work
on the same code in future. It can include information such
as developed by, modified by and it can also include incorporated
logic. Comments are ignored by the interpreter while execution.
Comments in VBScript are denoted by two methods.
Any statement that starts with a Single Quote (‘) is treated as
comment. Following is the example:
<script language="vbscript" type="text/vbscript"$gt;
Any statement that starts with the keyword “REM”. Following is the example:
<script language="vbscript" type="text/vbscript">
<!—
REM This Script is written to Validate the Entered Input
REM Modified by : Tutorials point/user2
//- >
</script>
Not all the modern browsers support VBScript. VBScript
is supported just by Microsoft's Internet Explorer
while other browsers (Firefox and Chrome) support
just JavaScript. Hence, developers normally prefer
JavaScript over VBScript.
Though Internet Explorer (IE) supports VBScript,
you may need to enable or disable this feature
manually. This tutorial will make you aware of the
procedure of enabling and disabling VBScript support in Internet Explorer.
VBScript in Internet Explorer
Here are simple steps to turn on or turn off VBScript in your Internet Explorer:
• Follow Tools -> Internet Options from the menu
• Select Security tab from the dialog box
• Click the Custom Level button
• Scroll down till you find Scripting option
• Select Enable radio button under Active scripting
• Finally click OK and come out
To disable VBScript support in your Internet Explorer, you need
to select Disable radio button under Active scripting.
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