book

VBScript in a Nutshell

by Matt Childs, Paul Lomax, Ron Petrusha

May 1995

Beginner

508 pages

16h 14m

English

O'Reilly Media, Inc.

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VBScript in a Nutshell
Preface
Why This Book?
Who Should Read This Book?
How This Book Should Be Used
If You’re New to VBScriptIf You’re a VBScript ProgrammerIf You’re a VB or VBA Developer New to VBScript
How This Book Is Structured
The Format of the Language Reference
Conventions in This Book
How To Contact Us
Call for Additions and Amendments
I. The Basics
1. Introduction
VBScript’s History and Uses
What VBScript Is Used For: Gluing Together Objects
PropertiesMethodsEvents

Differences Between VBScript and VBA
2. Program Structure
Functions and ProceduresDefining Subroutines: The Sub . . . End Sub ConstructCalling a SubroutineDefining Functions: The Function . . . End Function ConstructPassing Variables into a SubroutineExiting a Routine with the Exit Statement
Class Modules
The Class ConstructClass VariablesClass PropertiesClass MethodsClass Events
The Script Level
Active Server PagesWindows Script HostClient-Side Scripts for MSIEOutlook Forms
Reusable Code Libraries
Active Server PagesWindows Script HostClient-Side Scripts for MSIE
3. Data Types and Variables
VBScript Data Types: The Many Faces of the VariantVariant Data SubtypesDetermining the Variant SubtypeVarTypeTypeNameConverting from One Data Subtype to Another
Variables and Constants
What Is a Variable?What Is a Constant?Intrinsic ConstantsConstants in Type LibrariesDeclaring Variables and ConstantsOption ExplicitArray VariablesFixed arraysDynamic arraysDetermining array boundaries: UBound and LBoundMultidimensional arraysDynamic Multidimensional ArraysUsing UBound with multidimensional arraysScopeScript-level scopeProcedure-level scopePublic ScopePrivate
4. Error Handling and Debugging
DebuggingSyntax ErrorsSyntax errors at compile timeSyntax errors at runtimeLogical ErrorsLogical errors that affect program resultsLogical errors that generate error messagesThe Microsoft Script DebuggerLaunching the Script DebuggerThe Script Debugger interfaceTracing execution with the Script DebuggerDetermining the value of a variable, expression, or function at runtimeChanging variable values at runtime
Error Handling
The On Error Resume Next StatementThe Err ObjectErr object propertiesErr object methods
Common Problems Areas, and How to Avoid Them
5. VBScript with Active Server Pages
How ASP WorksThe global.asa FileIncluding Server-Side Script in Web Pages
Active Server Pages Object Model
ApplicationObjectContextRequestResponseServerSession
6. Programming Outlook Forms
Why Program Outlook Forms?
The Form-Based Development Environment
Interfaces and ObjectsOutlook Form Design ModeThe VBScript Environment
Running Your Code
Program Flow
The Outlook Object Model
The Current ItemThe Inspector ObjectThe Pages CollectionThe FormDescription ObjectThe NameSpace ObjectThe MAPIFolder ObjectOutlook Constants
Accessing Other Object Models
7. Windows Script Host
Why Use WSH?
Running WSH Scripts
Program Flow
Simple Script FilesScript Files with XML Code
The WSH Object Model
The WScript ObjectThe WshArguments ObjectThe WshEnvironment ObjectThe WshNetwork ObjectThe WshShell ObjectThe WshShortcut ObjectThe WshSpecialFolders ObjectThe WshUrlShortcut Object
WSH Language Elements
Accessing Other Object Models
8. VBScript with Internet Explorer
The <SCRIPT> Tag<SCRIPT> AttributesThe LANGUAGE attributeThe SRC attributeThe FOR attributeWhere to Place the <SCRIPT> TagUsing <!——> with <SCRIPT>
What Can You Do with Client-Side Scripting?
Interacting with the ClientHandling EventsData Validation
Understanding the IE Object Model
The Window ObjectThe Document ObjectThe Elements Collection and HTML Intrinsic ControlsThe textbox controlThe checkbox controlThe radio button controlThe list boxCommand button controlsThe History ObjectThe Event ObjectUsing the Document Object Model
II. Reference
9. The Language Reference
Abs Function
Array Function
Asc, AscB, AscW Functions
Atn Function
Call Statement
CBool Function
CByte Function
CCur Function
CDate Function
CDbl Function
Chr, ChrB, ChrW Functions
CInt Function
Class Statement
CLng Function
Const Statement
Cos Function
CreateObject Function
CSng Function
CStr Function
Date Function
DateAdd Function
DateDiff Function
DatePart Function
DateSerial Function
DateValue Function
Day Function
Dictionary Object
Dictionary.Add Method
Dictionary.CompareMode Property
Dictionary.Count Property
Dictionary.Exists Method
Dictionary.Item Property
Dictionary.Items Method
Dictionary.Key Property
Dictionary.Keys Method
Dictionary.Remove Method
Dictionary.RemoveAll Method
Dim Statement
Do . . . Loop Statement
Drive Object
Drives Collection Object
End . . . Statement
Erase Statement
Err Object
Err.Clear Method
Err.Description Property
Err.HelpContext Property
Err.HelpFile Property
Err.Number Property
Err.Raise Method
Err.Source Property
Escape Function
Eval Function
Execute Statement
Exit Statement
Exp Function
File Object
File.Copy Method
File.Delete Method
File.Move Method
File.OpenAsTextStream Method
File System Object Model
Files Collection Object
FileSystemObject Object
FileSystemObject.BuildPath Method
FileSystemObject.CopyFile Method
FileSystemObject.CopyFolder Method
FileSystemObject.CreateFolder Method
FileSystemObject.CreateTextFile Method
FileSystemObject.DeleteFile Method
FileSystemObject.DeleteFolder Method
FileSystemObject.DriveExists Method
FileSystemObject.Drives Property
FileSystemObject.FileExists Method
FileSystemObject.FolderExists Method
FileSystemObject.GetAbsolutePathName Method
FileSystemObject.GetBaseName Method
FileSystemObject.GetDrive Method
FileSystemObject.GetDriveName Method
FileSystemObject.GetExtensionName Method
FileSystemObject.GetFile Method
FileSystemObject.GetFileName Method
FileSystemObject.GetFileVersion Method
FileSystemObject.GetFolder Method
FileSystemObject.GetParentFolderName Method
FileSystemObject.GetSpecialFolder Method
FileSystemObject.GetStandardStream Method
FileSystemObject.GetTempName Method
FileSystemObject.MoveFile Method
FileSystemObject.MoveFolder Method
FileSystemObject.OpenTextFile Method
Filter Function
Fix Function
Folder Object
Folder.Copy Method
Folder.CreateTextFile Method
Folder.Delete Method
Folder.Move Method
Folders Collection Object
Folders.Add Method
For . . . Next Statement
For Each . . . Next Statement
FormatCurrency, FormatNumber, FormatPercent Functions
FormatDateTime Function
Function Statement
GetObject Function
GetRef Function
Hex Function
Hour Function
If . . . Then . . . Else Statement
Initialize Event
InputBox Function
InStr, InStrB Functions
InstrRev Function
Int Function
Is Operator
IsArray Function
IsDate Function
IsEmpty Function
IsNull Function
IsNumeric Function
IsObject Function
Join Function
LBound Function
LCase Function
Left, LeftB Functions
Len, LenB Functions
LoadPicture Function
Log Function
LTrim Function
Match Object
Matches Collection Object
Me Operator
Mid, MidB Functions
Minute Function
Month Function
MonthName Function
MsgBox Function
Now Function
Oct Function
On Error Statement
Option Explicit Statement
Private Statement
Property Get Statement
Property Let Statement
Property Set Statement
Public Statement
Randomize Statement
ReDim Statement
RegExp Object
RegExp.Execute Method
RegExp.Global Property
RegExp.IgnoreCase Property
RegExp.Pattern Property
RegExp.Replace Method
RegExp.Test Method
Rem Statement
Replace Function
RGB Function
Right, RightB Functions
Rnd Function
Round Function
RTrim Function
ScriptEngine Function
ScriptEngineBuildVersion Function
ScriptEngineMajorVersion Function
ScriptEngineMinorVersion Function
Second Function
Select Case Statement
Set Statement
Sgn Function
Sin Function
Space Function
Split Function
Sqr Function
StrComp Function
String Function
StrReverse Function
Sub Statement
Tan Function
Terminate Event
TextStream Object
TextStream.Close Method
TextStream.Read Method
TextStream.ReadAll Method
TextStream.ReadLine Method
TextStream.Skip Method
TextStream.SkipLine Method
TextStream.Write Method
TextStream.WriteBlankLines Method
TextStream.WriteLine Method
Time Function
Timer Function
TimeSerial Function
TimeValue Function
Trim Function
TypeName Function
UBound Function
UCase Function
Unescape function
VarType Function
Weekday Function
WeekdayName Function
While . . . Wend Statement
With Statement
Year Function
III. Appendixes
A. Language Elements by Category
Array Handling
Assignment
Comment
Constants
Data Subtype Conversion
Date and Time
Dictionary Object
Error Handling
File System Objects
Drive ObjectDrives Collection ObjectFile ObjectFiles Collection ObjectFileSystemObject ObjectFolder ObjectFolders Collection ObjectTextStreamObject
Information Functions
Mathematical and Numeric
Miscellaneous
Object Programming
Program Structure and Flow
String Manipulation
User Interaction
Variable Declaration
B. VBScript Constants
Color Constants
Comparison Constants
Date and Time Constants
Date Format Constants
Error Constant
Logical and TriState Constants
Message Box Constants
String Constants
Variable Type Constants
C. Operators
Arithmetic Operators
String Operator
Comparison Operators
The Is operator
Logical and Bitwise Operators
Operator Precedence
Index
Colophon

Content preview from VBScript in a Nutshell

Name

RTrim Function

Syntax

RTrim(stringexp)

stringexp

Use: Required

Data Subtype: String

A valid string expression.

Return Value

A Variant of subtype String.

Description

Removes any trailing spaces from stringexp.

Rules at a Glance

If stringexp contains a Null, RTrim returns Null.

Programming Tips & Gotchas

Unless you need to keep leading spaces, you should use the Trim function, which is the equivalent of RTrim(LTrim( string )), thereby clearing both leading and trailing spaces in a single function call.

VB/VBA Differences

Because it does not support strong typing, VBScript does not support the VBA RTrim$ function, which returns a strongly typed string rather than a string variant.