# $IFNDEF directive

The $IFNDEF directive tests for the absence of a definition for an identifier in the
 compiler symbol table.

## Syntax

```
$IFNDEF identifier statements
{$ELSE statements}
$ENDIF
```

## Parameter(s)

| 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. |

## See also

- [$DEFINE directive](https://d3codex.com/pickbasic-flashbasic/define-directive/)
- [Compiler directives](https://d3codex.com/pickbasic-flashbasic/compiler-directives/)

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Source: https://d3codex.com/pickbasic-flashbasic/ifndef-directive/ - part of the D3Codex reference.