Programming tools / The preprocessor |
Un-defines a preprocessor macro.
&undef identifier
If a macro is redefined without having been undefined previously, the preprocessor issues a warning and replaces the existing definition with the new one. First un-define a macro with the &undef directive.
&define HELLO "hello" DISPLAY HELLO &undef HELLO DISPLAY HELLO
& 1 "A" DISPLAY "hello" DISPLAY HELLO