&UNDEFINE preprocessor directive
- Last Updated: February 11, 2026
- 1 minute read
- OpenEdge
- Version 13.0
- Documentation
Undefines a compile-time constant (preprocessor name).
Syntax
|
- preprocessor-name
- The preprocessor name (compile-time constant) that you want to undefine.
Notes
- When you use the
&UNDEFINEdirective, ABL warns you if the name you want to undefine was not previously defined. - The
&UNDEFINEdirective undefines the currently active name. It also undefines named include file arguments. - To globally define the same name more than once, use this directive to
undefine the name before redefining it. If you do not undefine the global name before
redefining it, the compiler produces a warning message for non-globally (scoped) defined
names. For globally defined names,
&UNDEFINEis optional, but recommended for code readability. If&UNDEFINEis not used, the last&GLOBAL-DEFINEstatement is used.
See also
&GLOBAL-DEFINE preprocessor directive, &SCOPED-DEFINE preprocessor directive, DEFINED preprocessor function