>>>>> "D" == Dani <danicy...@gmail.com> >>>>> on Tue, 24 Feb 2009 14:09:36 -0800 writes:
D> Hi list, D> I don't know if somebody has spent a lot of time debugging strange D> problems with if else positioning - the parser seems to recognize only D> the syntax bellow - this is the only way of making these pieces of D> code to work. D> As far as i'm concerned, no examples were available (it would be so D> awesome to have them in the introductory manual!) D> #Try to change the placement of the keywords and you are dead! ["dead"?] Oh dear... Note this has nothing to do with if( ) .. else .. but indeed with how things are parsed. I think this is FAQ (or should become one): ?if [the help page you really should read before spending too much time or even post to R-help] has the following section > Note that it is a common mistake to forget to put braces ('{ .. }') > around your statements, e.g., after 'if(..)' or 'for(....)'. > In particular, you should not have a newline between '}' and > 'else' to avoid a syntax error in entering a 'if ... else' > construct at the keyboard or via 'source'. For that reason, one > (somewhat extreme) attitude of defensive programming is to always > use braces, e.g., for 'if' clauses. Regards, Martin Maechler, ETH Zurich D> Ex1: D> if (1==1){ D> print('if') D> print('if again') D> }else D> print('else') D> Ex2: D> if (2==2) print('if') else print('else') D> Ex3: D> if (2==2){ D> print('if') D> print('if again') D> }else D> { D> print('else') D> print('else2') D> } D> Ex4: D> if (2==2){ D> print('if') D> print('if again') D> }else print('else') D> cheers, D> ------------------------------------- D> Daniela D> ______________________________________________ D> R-help@r-project.org mailing list D> https://stat.ethz.ch/mailman/listinfo/r-help D> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html D> and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.