SmartPascal $IfNDef Compiler Directive Executes code if a conditional symbol has not been defined

{$IfNDef Symbol}   ... Code to run when the symbol is defined ...   {$Else}   ... Code to run when the symbol is not defined ...   {$EndIf}

Description The $IfNDef compiler directive starts a section of conditionally compiled code. Only if the specified Symbol has not been defined.   Symbols come in two types. Predefined in Delphi, such as Console when running a console application. And defined by the $Define compiler direcctive.   $IfDef is very useful when developing code, allowing various sections to be compiled when testing. Related commands $Define Defines a compiler directive symbol - as used by IfDef $Else Starts the alternate section of an IfDef or IfNDef $EndIf Terminates conditional code compilation $IfDef Executes code if a conditional symbol has been defined $IfOpt Tests for the state of a Compiler directive $UnDef Undefines a compiler directive symbol - as used by IfDef		Example code : Setting up and using a user defined symbol begin   // Set our code into dangerous mode   {$Define DANGERMODE}   // Are we out of danger?   {$IfNDef DANGERMODE}   ShowMessage('We are out danger at present');   {$Else}   ShowMessage('We are in danger mode!');   {$EndIf}   // Switch off danger mode   {$UnDef DANGERMODE} end; Show full unit code    We are in danger mode!