The following predefined variables are available for conditional compilation. If a variable is not true, it is not defined and behaves as NaN when accessed.
| Variable | Description |
|---|---|
| @_win32 | True if running on a Win32 system. |
| @_win16 | True if running on a Win16 system. |
| @_mac | True if running on an Apple Macintosh system. |
| @_alpha | True if running on a DEC Alpha processor. |
| @_x86 | True if running on an Intel processor. |
| @_mc680x0 | True if running on a Motorola 680x0 processor. |
| @_PowerPC | True if running on a Motorola PowerPC processor. |
| @_jscript | Always true. |
| @_jscript_build | Contains the build number of the JScript scripting engine. |
| @_jscript_version | Contains the JScript version number in major.minor format. |