Basic Constants

Constants used in Basic programs

Boolean constants

Nome	Tipo	Valor
True	Boolean	1
False	Boolean	0

Exemplo:


            Dim bPositive as Boolean
            bPositive = True

Mathematical constant

Nome	Tipo	Valor
Pi	Double	3.14159265358979

Exemplo:


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

Object Constants

Nome	Tipo	Uso
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.

Exemplo:


            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	Valor hexadecimal (decimal)	Descrición
vbTrue	-1	Part of vbTriState enumeration.
vbFalse	0	Part of vbTriState enumeration.
vbUseDefault	-2	Part of vbTriState enumeration.
vbCr	\x0D (13)	CR - Retorno de carro
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