Basic Constants

Constants used in Basic programs

Boolean constants

Name	Type	Value
True	Boolean	1
False	Boolean	0

Example:


        Dim bPositive as Boolean
        bPositive = True

Mathematical constant

Name	Type	Value
Pi	Double	3.14159265358979

Example:


        Function Rad2Deg( aRad as Double) As Double
         Rad2Deg = aRad * 180.00 / Pi
        End Function

Object Constants

Name	Type	Usage
Empty	Variant	The Empty value indicates that the variable is not initialized.
Null	null	Indicates that the variable does not contain data.
Nothing	Object	Assign the Nothing object to a variable to remove a previous assignment.

Example:


        SubExampleEmpty
        Dim sVar As Variant
         sVar = Empty
         Print IsEmpty(sVar) ' Returns True
        End Sub
        Sub ExampleNull
        Dim vVar As Variant
         MsgBox IsNull(vVar)
        End Sub
        Sub ExampleNothing
        Dim oDoc As Object
         Set oDoc = ThisComponent
         Print oDoc.Title
         oDoc = Nothing
         Print oDoc ‘ Error
        End Sub

Additional VBA constants

The following constants are available when VBA compatibility mode is enabled

This function or constant is enabled with the statement Option VBASupport 1 placed before the executable program code in a module.

Named constant	Hexadecimal (decimal) value	Description
vbTrue	-1	Part of vbTriState enumeration.
vbFalse	0	Part of vbTriState enumeration.
vbUseDefault	-2	Part of vbTriState enumeration.
vbCr	\x0D (13)	CR - Carriage return
vbCrLf	\x0D\x0A (13 10)	CRLF - Carriage return and line feed
vbFormFeed	\x0c (12)	FF - Form feed
vbLf	\x0A (10)	LF - Line feed
vbNewLine	\x0D\x0A (13 10) for 32-bit Windows \x0A (10) for other 64-bit systems	LF or CRLF
vbNullString	""	Null string
vbTab	\x09 (9)	HT - Horizontal tab
vbVerticalTab	\x0B (11)	VT - Vertical tab