VBS by George Hernandez

VBScript is the dominant and default scripting language for server-side processing via ASPs (Active Server Pages) on Microsoft's web server: IIS (Internet Information Server/Services). VBS and JS can also be used for WSH (Windows Scripting Host) which is the replacement for the old batch files (.bat) and can run directly in the operating system. EGs: See my section on ASP.

VBScript can also be used for client-side processing. (Please note that JavaScript is preferred for client-side scripting because VBS is not supported by Netscape Navigator, whereas JS is supported by both Netscape and Microsoft browsers.) For client-side processing, VBScript is enclosed by <script> tags. VBScript is usually further enclosed within HTML comment tags in case the user's browser is not enabled for VBScript.

Here's how VBS and VB features relate:

Comments are the same as in VB: An apostrophe (') is placed at the start of the comment. Comments cannot utilize line continuation.
Line continuation is the same as in VB: A long statement can be broken into several lines by appending at the end of each continued line a space and underscore ( _).
Case and white space are the same as in VB: Immaterial (unlike in JavaScript!).
Most of the operators are the same as VB Operators.
Most of the flow control statement are the same as VB Flow Control.
Most of the procedures are the same as VB Procedures except that the Friend and Static keywords cannot be used and all arguments passed are ByRef (ie the procedure can change the variable's value). Also parameter cannot use the Optional keyword.
Variables are somewhat different in VBS:
- VBScript has only one datatype: variant.
- The VarType() function can return the subtype stored by the variant variable. The subtypes for VBS are the same as VB DataTypes except that Null and Empty will show as separate subtype by VarType(). Note that Empty will translate to 0 for numeric variables or empty string ("") for string variables.
- Name restrictions and arrays are handled similarly. See VB Identifiers.
- There are only two levels of variable scope in VBScript. There is no global scope or Friend scope.
  - Module/Script scope variables are declared outside of procedures.
  - Procedure level variables are declared within procedures.
Most of the VBS naming conventions are the same as listed in VB Identifiers.
Note that VBS error codes for syntax errors are of syntax 10XX. All other VBS errors are probably run-time errors.
VBS has a smaller set of objects than VB.
- Class
- Dictionary
- Err
- FileSystemObject
- Match
- RegExp
Error control via On Error Goto Label is not supported by VBS. However you can use On Error Resume Next, On Error GoTo 0, and the Err object. See "Doctor Scripto's Script Shop" [http://www.microsoft.com/technet/scriptcenter/resources/scriptshop/shop1205.mspx].
The Format() function.

VBS Functions

The functions used by VBS are similar to the VB functions. The items in bold are new to VB 5.6 (MSIE 6): CStr, Escape, and Unescape.

Abs	Array	Asc	Atn
CBool	CByte	CCur	CDate
CDbl	Chr	CInt	CLng
Conversions	Cos	CreateObject	CSng
CStr	Date	DateAdd	DateDiff
DatePart	DateSerial	DateValue	Day
Derived Math	Escape	Eval	Exp
Filter	FormatCurrency	FormatDateTime	FormatNumber
FormatPercent	GetLocale	GetObject	GetRef
Hex	Hour	InputBox	InStr
InStrRev	Int, Fix	IsArray	IsDate
IsEmpty	IsNull	IsNumeric	IsObject
Join	LBound	LCase	Left
Len	LoadPicture	Log	LTrim; RTrim; and Trim
Maths	Mid	Minute	Month
MonthName	MsgBox	Now	Oct
Replace	RGB	Right	Rnd
Round	ScriptEngine	ScriptEngineBuildVersion	ScriptEngineMajorVersion
ScriptEngineMinorVersion	Second	SetLocale	Sgn
Sin	Space	Split	Sqr
StrComp	String	StrReverse	Tan
Time	Timer	TimeSerial	TimeValue
TypeName	UBound	UCase	Unescape
VarType	Weekday	WeekdayName	Year

Note that there are variations of the VB Format() function but the Format() function itself is not available to VBS.

Certain functions (EG: InputBox() and MsgBox()) are designed for client-side code and should not be used in server-side code.

Here's some handy VBS code

Check for email address format

This checks if a control has a value that follows minimal syntax requirements for email addresses.

Function ValidEmail()
  Dim re, str
  Set e = window.event.srcelement
  str = e.value
  If Len(Trim(str)) > 0 Then
    Set re = new RegExp
    re.Pattern = "(\w+)@(\w+)\.(\w+)"
    If Not(re.Test(str)) Then
      Alert("You have entered an invalid email format")
      e.focus
    End If
    Set re = Nothing
  End If
  Set e = Nothing
End Function

Get values from select box

This is VBS client side code that gets the value and displayed text from the selected option in a select list.

This is in the header:

<script language="VBScript"><!--
Sub selX_OnBlur()
  MsgBox "value=" & selX.value & "    " & _
         "text=" & selX.options(selX.selectedIndex).text
End Sub
' --></script>

This is the select box:

<select name="selX">
  <option value="1">Ape</option>
  <option value="2">Bee</option>
  <option value="3">Cat</option>
</select>

Page Modified: (Hand noted: 2007-10-03 18:55:04Z) (Auto noted: 2008-02-04 22:45:36Z)