Syntax:
#ELSE can be specified after a #IFDEF or #IFNDEF directive as an alternative. Lines following #ELSE are read only if the preceding #IFDEF or #IFNDEF was not accepted.
They are skipped until the keyword #ENDIF is encountered, after which normal processing is resumed.
Example :
In the above example, /usr/lib/fpc/2.6.2/linuxunits will be added to the path if you’re compiling with version 2.6.2 of the compiler, otherwise /usr/lib/fpc/2.6.0/linuxunits will be added to the path.