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 constant, function or object 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 Windows \x0A (10) for other systems	LF or CRLF
vbNullString	""	Null string
vbTab	\x09 (9)	HT - Horizontal tab
vbVerticalTab	\x0B (11)	VT - Vertical tab