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Appendix C

VBScript Reference of Syntax, Methods, and Functions

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This appendix summarizes the statements, functions, and operators used in the Visual Basic Scripting Edition.

Category/Keyword	Type	Usage
Arithmetic
Atn	Function	Returns the arctangent of a number Atn(number)
Cos	Function	Returns the cosine of an angle Cos(number)
Exp	Function	Returns a number raised to a power Exp(number)
Log	Function	Returns the logarithm of a number Log(number)
Randomize	Statement	Primes the internal random number generator Randomize (See Chapter 11, "Real-Life Examples I")
Rnd	Function	Returns a random number Rnd (See Chapter 11)
Sin	Function	Returns the sine of an angle Sin(number)
Sqr	Function	Returns the square root of a number Sqr(number)
Tan	Function	Returns the tangent of an angle Tan(number)
Array handling
Dim	Statement	Declares an array Dim arrayname([subscripts]) (See Chapter 4 "Using the VBScript Language")
Erase	Statement	Clears the contents of an array Erase arrayname
IsArray	Function	Returns True if var is an array, and False if not IsArray(var)
Lbound	Function	In VBScript, always returns 0 Lbound(arrayname)
Preserve	Statement	Copies the contents of a dynamic array to a resized dynamic array Redim Preserve arrayname(subscripts)
ReDim	Statement	Declares a dynamic array or redimensions a dynamic array (see Preserve) ReDim arrayname() or ReDim arrayname([subscripts])
UBound	Statement	Returns the largest subscript of an array Ubound(arrayname)
Assignment
=	Operator	Assigns a value to a variable or property variable = value (See Chapter 4)
Set	Statement	Assigns an object reference to a variable Set variable = object
Comment
Rem	Statement	Declares the following line as a comment to be ignored by the language engine Rem comment_text
Constants/Literals
Empty	Literal	Declares a special uninitialized variable value variable = Empty (See Chapter 4)
False	Constant	A Boolean value representing 0 variable = False (See Chapter 4)
Nothing	Literal	Used to disassociate an object reference from a variable; used in conjunction with Set Set variable = Nothing (See Chapter 4)
Null	Literal	Represents no valid data variable = Null (See Chapter 4)
True	Constant	Boolean value representing -1 variable = True (See Chapter 4)
Conversions
Abs	Function	Returns the unsigned (absolute) value of a number Abs(number)
Asc	Function	Returns the ANSI/ASCII code of a character Asc(string) (See Chapter 3 "Communicating with Your Users")
CBool	Function	Returns a Boolean subtype Variant value from any valid expression CBool(expression)
CByte	Function	Returns a Byte subtype Variant value from any valid expression Cbyte(expression)
CDate	Function	Returns a Date subtype Variant value from any valid date expression CDate(expression)
CDbl	Function	Returns a Double Precision subtype Variant value from any valid numeric expression CDbl(expression)
Chr	Function	Returns the character corresponding to the ANSI or ASCII code Chr(number)
CInt	Function	Returns an Integer subtype Variant value from any valid numeric expression CInt(expression)
CLng	Function	Returns a Long Integer subtype Variant value from any valid numeric expression CLng(expression)
CSng	Function	Returns a Single Precision subtype Variant value from any valid numeric expression CSng(expression)
CStr	Function	Returns a String subtype Variant value from any valid expression CStr(expression)
DateSerial	Function	Returns a Date subtype Variant from valid year, month, and day values DateSerial(year,month,day)
DateValue	Function	Returns a Date subtype Variant value from any valid date expression DateValue(expression)
Hex	Function	Returns a String subtype Variant representing the hexadecimal value of a number Hex(number)
Int	Function	Returns an Integer subtype Variant rounded down from the number supplied Int(number)
Fix	Function	Returns an Integer subtype Variant rounded up from the number supplied Fix(number)
Oct	Function	Returns a String subtype Variant representing the octal value of a number Hex(number)
Sgn	Function	Returns an Integer subtype Variant representing the sign of a number Sgn(number) values > 0 return 1 values = 0 return 0 values < 0 return -1
TimeSerial	Function	Returns a Date subtype Variant from valid hour, minute, and second values TimeSerial(hour,minute,second)
TimeValue	Function	Returns a Date subtype Variant value from any valid time expression TimeValue(expression)
Dates and Times
Date	Function	Returns the current system date Date()
DateSerial	Function	Returns a Date subtype Variant from valid year, month, and day values. DateSerial(year,month,day)
DateValue	Function	Returns a Date subtype Variant value from any valid date expression. DateValue(expression)
Day	Function	Returns an Integer subtype Variant representing the day (1-31) from a valid date expression Day(dateexpression)
Hour	Function	Returns an Integer subtype Variant representing the hour (0-23) from a valid time expression Hour(timeexpression)
Minute	Function	Returns an Integer subtype Variant representing the minute (0-60) from a valid time expression Minute(timeexpression)
Month	Function	Returns an Integer subtype Variant representing the month (1-12) from a valid date expression Month(dateexpression)
Now	Function	Returns the current date and time of the system Now()
Second	Function	Returns an Integer subtype Variant representing the second (0-60) from a valid time expression Second(timeexpression)
Time	Function	Returns the current system time Time()
TimeSerial	Function	Returns a Date subtype Variant from valid hour, minute and second values TimeSerial(hour,minute,second)
TimeValue	Function	Returns a Date subtype Variant value from any valid time expression TimeValue(expression)
Weekday	Function	Returns an Integer subtype Variant between 1 and 7 representing the day of the week, starting at Sunday, from a date expression Weekday(dateexpression)
Year	Function	Returns an Integer subtype Variant representing the year from a valid date expression Year(dateexpression)
Declarations
Dim	Statement	Declares a variable Dim variable
End	Statement	Declares the end of a Sub procedure or function End Sub End Function
Exit	Statement	Use with Do, For, Function, or Sub to prematurely exit the routine Exit Do/For/Function/Sub
Function	Statement	Declares a function and the argument list passed into the function, and declares the end of a function; also used with Exit to prematurely end a function Function functionname(argumentlist) Exit Function End Function Public variable
Sub	Statement	Declares a custom procedure or event handler and the argument list, if any, and declares the end of a custom procedure or event handler; also used with Exit to prematurely end a custom procedure or event handler Sub subroutinename([argumentlist]) Exit Sub End Sub
Error Handling
Clear	Method	A method of the Err object to reset the Err.Number property to 0 Err.Clear
Description	Property	A property of the Err object that contains a description of the last error as specified in the Err.Number property Err.Description
Err	Object	An object containing information about the last error Err.property|method
On Error	Statement	Used in conjunction with Resume Next to continue execution with the line directly following the line in which the error occurred On Error Resume Next
Raise	Method	A method of the Err object used to simulate the occurrence of an error specified by number Err.Raise(errornumber)
Number	Property	A property of the Err object that contains the error code for the last error, or 0 if no error has occurred Err.Number
Source	Property	Returns the name of the object or application that raised the error Err.Source
Input/Output
InputBox	Function	Displays a dialog box to allow user input InputBox(caption[,title][,value][,x][,y])
MsgBox	Function	Displays a dialog box MsgBox(prompt[, definition][, title])
Operators
+	Operator	Addition of two numerical expressions result = expr1 + expr2
And	Operator	Logical conjunction operator If expression AND expression Then
/	Operator	Division operator result = expression / expression
=	Operator	Equality operator If expression = expression Then
Eqv	Operator	Logical equivalence operator If expression Eqv expression Then
^	Operator	Exponentiation operator result = expression ^ expression
>	Operator	Greater than comparison If expression > expression Then
>=	Operator	Greater than or equal to comparison If expression >= expression Then
Imp	Operator	Logical implication If expression Imp expression Then
<>	Operator	Inequality comparison If expression <> expression Then
\	Operator	Integer division operator result = expression \ expression
<	Operator	Less than comparison If expression < expression Then
<=	Operator	Less than or equal to comparison If expression <= expression Then
Mod	Operator	Modulus arithmetic; returns only the remainder of a division of two numbers result = expression mod expression
*	Operator	Multiplication result = expression * expression
-	Operator	Subtraction result = expression - expression
Or	Operator	Logical disjunction If expression Or expression Then
&	Operator	Concatenation of two string values result = string & string
Xor	Operator	Logical exclusion If expression Xor expression Then
Options
Option	Statement	Forces a compile-time error if an Explicit undeclared variable is found Option Explicit
Program Flow
Call	Statement	Passes execution to a subroutine or event handler; also can be used to replicate the actions of the user Call myroutine() Call cmdbutton_OnClick()
Do...Loop	Statement	Repeats code while a condition is met or until a condition is met Do While condition ... Loop or Do Until condition ... Loop or Do ... Loop While condition or Do ... Loop Until condition
For...Next	Statement	Repeats a block of code until the counter reaches a given number For counter = lower to upper [step] ... Next
If...Then...Else	Statement	Conditional execution of code If condition Then ... (if condition met Else) ... (if condition not met) End If
Select Case	Statement	Selective execution of code, where
		testexpression must match expression Select Case testexpression Case expression ... Case expression ... Case Else End Select
While...Wend	Statement	Execution of a code block while a condition is met While expression ... Wend
Strings
InStr	Function	Returns the starting point of one string within another string, or 0 if not found result = InStr(start,searched,sought)
Lcase	Function	Converts a string to lowercase result = LCase(string)
Left	Function	Returns the n leftmost characters of a string result = LCase(string)
Len	Function	Returns the length of a string result = Len(string)
Ltrim	Function	Removes all leading spaces result = LTrim(string)
Mid	Function	Returns a string of length L, starting at S within string result = Mid(string, S, L)
Right	Function	Returns the rightmost n characters result = Right(string, n)
RTrim	Function	Removes all trailing spaces from a string result = RTrim(string)
Space	Function	Returns a string consisting of n spaces result = Space(n)
StrComp	Function	Returns an Integer subtype Variant representing the result of a comparison of two strings result = StrComp(string1, string2) string1 < string2 returns -1 string1 < string2 returns 0 string1 < string2 returns 1
String	Function	Returns a string consisting of character C, of length L result = String(L, C)
Trim	Function	Removes both leading and trailing spaces result = Trim(string)
UCase	Function	Returns a string as uppercase alphabetical characters result = UCase(string)
Variants
IsArray	Function	Returns True (-1) if expression is an array, and False (0) if not result = IsArray(expression)
IsDate	Function	Returns True (-1) if expression is a valid date and False (0) if not result = IsDate(expression)
IsEmpty	Function	Returns True (-1) if expression equates to an Empty subtype and False (0) if not result = IsEmpty(expression)
IsNull	Function	Returns True (-1) if expression equates to a Null subtype and False (0) if not result = IsNull(expression)
IsNumeric	Function	Returns True (-1) if expression is a valid numeric expression and False (0) if not result = IsNumeric(expression)
VarType	Function	Returns an integer representing the sub data type of a Variant result = VarType(expression)

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