The $IFNDEF directive tests for the absence of a definition for an identifier in the compiler symbol table.
$IFNDEF identifier statements
{$ELSE statements}
$ENDIF
| identifier |
Specifies the symbol to be tested. If the symbol is not defined in the symbol table (by $DEFINE), statements following the identifier are executed. If the symbol is defined in the symbol table (by $DEFINE), the statements in the $ELSE clause are executed if specified. The $ENDIF directive is required. |
| $ELSE | (Optional) If the symbol is defined, the statements in the $ELSE clause are executed if specified. |
| $ENDIF | (Required) The $ENDIF directive marks the end of the $IFNDEF directive. |