Appendix D VBScript Language Reference This appendix summarizes the statements, functions, and operators used in the Visual Basic Scripting Edition. Category/Keyword Arithmetic Type Usage 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 Rnd Function Returns a random number Rnd 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]) 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 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 False Constant A Boolean value representing 0 variable = False Nothing Literal Used to disassociate an object reference from a variable; used in conjunction with Set Set variable = Nothing Null Literal Represents no valid data variable = Null True Constant Boolean value representing -1 variable = True 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) 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 value 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 value representing the hexadecimal value of a number Hex(number) Int Function Returns an Integer subtype Variant value rounded down from the number supplied Int(number) Fix Function Returns an Integer subtype Variant value rounded up from the number supplied Fix(number) Oct Function Returns a String subtype Variant value representing the octal value of a number Hex(number) Sgn Function Returns an Integer subtype Variant value 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 value 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 value 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 value representing the day (1-31) from a valid date expression Day(dateexpression) Hour Function Returns an Integer subtype Variant value representing the hour (0-23) from a valid time expression Hour(timeexpression) Minute Function Returns an Integer subtype Variant value representing the minute (0-60) from a valid time expression Minute(timeexpression) Month Function Returns an Integer subtype Variant value 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 value 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 value 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 value 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 sub-routine 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 character 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 character 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 subtype of a Variant result = VarType(expression)