-define (Visual Basic)

Defines conditional compiler constants.

Syntax

-define:["]symbol[=value][,symbol[=value]]["]  

or

-d:["]symbol[=value][,symbol[=value]]["]  

Arguments

Term	Definition
symbol	Required. The symbol to define.
value	Optional. The value to assign symbol. If value is a string, it must be surrounded by backslash/quotation-mark sequences (\") instead of quotation marks. If no value is specified, then it is taken to be True.

Remarks

The -define option has an effect similar to using a #Const preprocessor directive in your source file, except that constants defined with -define are public and apply to all files in the project.

You can use symbols created by this option with the #If...Then...#Else directive to compile source files conditionally.

-d is the short form of -define.

You can define multiple symbols with -define by using a comma to separate symbol definitions.

To set -define in the Visual Studio integrated development environment
1. Have a project selected in Solution Explorer. On the Project menu, click Properties. 2. Click the Compile tab. 3. Click Advanced. 4. Modify the value in the Custom Constants box.

Example

The following code defines and then uses two conditional compiler constants.

    ' Vbc /define:DEBUGMODE=True,TRAPERRORS=False test.vb
    Sub mysub()
#If debugmode Then
        ' Insert debug statements here.
         MsgBox("debug mode")
#Else
        ' Insert default statements here.
#End If
    End Sub

See also

• Visual Basic Command-Line Compiler
• #If...Then...#Else Directives
• #Const Directive
• Sample Compilation Command Lines