Where do I define symbols tested with {$IFDEF}?

Question

When I use Delphi directives in code, like:

{$IFDEF something}
.
.
.
{$ENDIF}

Where do I assign the word \'something\' in the project? I tried

Answer 1

You can define global symbols in external file with .inc extension. Create a new text file, put in it all you defines and save it as for instance Predefines.inc:

--- Content of the file Predefines.inc ---

{$DEFINE Symbol}
{$IFDEF Symbol}
  {$DEFINE AnotherSymbol}
{$ENDIF}

In you Delphi modules, where you need to check are symbols defined, put this code in interface section:

interface

{$I Predefines.inc}

uses ...

// Check you defines

{$IFDEF Symbol}
...
{$ENDIF}