> -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of Antonio Paredes > Sent: Saturday, October 03, 2009 5:53 PM > To: r-help@r-project.org > Subject: [R] Stranger Behavior -maybe not > > Hello everyone, > > When I run a for loop I noticed that the looping variable > gets assigned the > last value in the loop: > > For example, if I let h=200, and I run > > for(i in 1:h), > > i gets the value 200. What's wrong here?
That is the way for loops work in R. After the loop is done 'i' remains defined to be the last value it had in the loop, just as any other variable defined in the loop would remain defined. In S+ (and S) the 'i' in the loop is defined only within the loop and disappears after the loop is done. If another 'i' were defined before the start of the loop then it would be masked by the loop's 'i' until the loop was done and the pre-loop value of 'i' would then reappear. I.e., the for loop acted a bit like a new frame, but unlike the usual frames in S+. (C++ acts like this, doesn't it, if the 'i' is declared in the for statement. R and S don't have declarations so the analogy isn't good.) E.g., RS> i<-7 RS> for(i in 1:3)if(i==2)break RS> i S+: [1] 7 R : [1] 2 Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > > -- > -Tony > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > ______________________________________________ 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.
