Constants Declared by Visual Basic
Visual Basic provides a number of predefined constants for developers for use in conditional compilation as well as in printing and displaying data.
Conditional Compilation Constants
The following table lists the predefined constants available for conditional compilation.
Constant |
Description |
---|---|
CONFIG |
A string that corresponds to the current setting of the Active Solution Configuration box in the Configuration Manager. |
DEBUG |
A Boolean value that can be set in the Project Properties dialog box. By default, the Debug configuration for a project defines DEBUG. When DEBUG is defined, Debug class methods generate output to the Output window. When it is not defined, Debug class methods are not compiled and no Debug output is generated. |
TARGET |
A string representing the output type for the project or the setting of the command-line /target option. The possible values of TARGET are:
|
TRACE |
A Boolean value that can be set in the Project Properties dialog box. By default, all configurations for a project define TRACE. When TRACE is defined, Trace class methods generate output to the Output window. When it is not defined, Trace class methods are not compiled and no Trace output is generated. |
VBC_VER |
A number representing the Visual Basic version, in major.minor format. The version number for Visual Basic 2005 is 8.0. |
Print and Display Constants
When you call print and display functions, you can use the following constants in your code in place of the actual values.
Constant |
Description |
---|---|
vbCrLf |
Carriage return/linefeed character combination. |
vbCr |
Carriage return character. |
vbLf |
Linefeed character. |
vbNewLine |
Newline character. |
vbNullChar |
Character having a value of 0. |
vbNullString |
Not the same as a zero-length string (""); used for calling external procedures. |
vbObjectError |
Error number. User-defined error numbers should be greater than this value. For example: Err.Raise(Number) = vbObjectError + 1000 |
vbTab |
Tab character. |
vbBack |
Backspace character. |
vbFormFeed |
Not used in Microsoft Windows. |
vbVerticalTab |
Not useful in Microsoft Windows. |