D:\tmp\pm>perl -MO=Deparse print "a"=> =>"c"; print "d",,"e"; print ,"f"; print =>"d"; __END__ print 'a', 'c'; print 'd', 'e'; print($_), '???'; # comma seen as scalar comma separator '???', '???'; # "print" seen as hash-key, void constants folded away __DATA__ D:\tmp\pm>perl -MO=Deparse print (, "b"); print (=> "g"); __END__ syntax error at - line 1, near "print (," syntax error at - line 2, near "print (=>" - had compilation errors. __DATA__