Contents

# Property Statement

A property, also called field or attribute, characterizes a given object or piece of information. Properties can be used to control access to data. It is common use to include instructions at setting or reading time of properties. Code can vary from simple assignment to complex context dependent routines. Using Get, Let or Set accessors enforces properties' consistency when necessary.

This statement requires Option Compatible to be placed before the executable program code in a module.

### Syntax:

             [Private | Public] Property Get name[char | As typename]
             End Property

             [Private | Public] Property [Let | Set] name[char] [([Optional [ByRef | ByVal]]value[char | As typename])] [As typename]
             End Property

### Parameters:

name: The property name.

argument: Value to be passed to the Property setter routine.

Property setters often use a single argument. Multiple arguments are equally accepted.

##### argument fragment

          {[Optional [ByRef|ByVal]]|ParamArray} argument {{As typename|char}[ = expression]|[()]As Variant}

##### Parameters

Optional: The argument is not mandatory.

ByRef: The argument is passed by reference. ByRef is the default.

ByVal: The argument is passed by value. Its value can be modified by the called routine.

char: Type declaration character.

typename: Primitive data type name. Library or module defined types can also be specified.

= expression: Specify a default value for the argument, matching its declared type. Optional is necessary for each argument specifying a default value.

ParamArray: Use ParamArray when the number of parameters is undetermined. A typical scenario is that of a Calc user-defined function. Using ParamArray should be limited to the last argument of a routine.

UsingParamArray or = expression require Option Compatible to be placed before the executable program code in a module.

When using Option VBASupport 1, Optional arguments with no default value (= expression) are initialized according to their data type, except if Variant.

##### typename fragment

          {Boolean|Byte|Currency|Date|Double|Integer|Long|Object|Single|String|Variant}

##### char fragment

          { % | & | ! | # | $ | @ }

## Examples

          Option Compatible
          Sub Main
              ProductName = "Office"
              Print ProductName ' displays "LibreOfficeDev"
          End Sub

          Private _office As String
          Property Get ProductName As String
              ProductName = _office
          End Property
          Property Let ProductName(value As String)
              _office = "Libre"& value
          End Property

In the absence of Property Let or Property Set, Property Get helps define protected information, which can not be accidently altered by a foreign module:

          Option Compatible
          Public Property Get PathDelimiter As String ' Read-only variable
              Static this As String
              If this = "" Then : Select Case GetGuiType()
                  Case 1 : this = ";" ' Windows
                  Case 4 : this = ":" ' Linux or macOS
                  Case Else : Error 423 ' Property or method not defined: PathDelimiter
              End Select : End If
              PathDelimiter = this
          End Property ' read-only PathDelimiter

          Sub Main
              PathDelimiter = "a sentence" ' does nothing
          End Sub

Use Let or Set when handling UNO services or class objects:

          Option Compatible
          Sub Main
              'Set anObject = CreateUnoService( "com.sun.star.frame.Desktop" )
              anObject = CreateUnoService( "com.sun.star.frame.Desktop" )
              Print anObject.SupportedServiceNames(0) ' displays "com.sun.star.frame.Frame"
          End Sub

          Property Get anObject As Object
              Set anObject = _obj
          End Property

          Private _obj As Object

          'Property Set anObject(value As Object)
              'Set _obj = value.CurrentFrame
          'End Property
          Property Let anObject(value As Object)
              Set _obj = value.CurrentFrame
          End Property

Related Topics

Subroutines basics

Using Procedures, Functions and Properties

Function Statement

Sub Statement

End, Exit statements

Option ClassModule Statement

Option Compatible Statement