It's not a bug. It's the intended behavior.
Sprintf by itself returns a formatted character string and doesn't print
anything. Without the return statement, the function returns the string, which
the interactive processor then prints (since that's what it does when you
simply present it with an object).
To get the same behavior inside the function and still return the value 'a',
just do this:
x <- function() { a <- 888
+ print(sprintf("xxx %s", a) )
+ return(a) }
That just makes explicit what the combination of function + interaction is
doing implicitly.
Good luck!
--
Jeremy Raw, PE, AICP
Senior Modeling Systems Analyst
Virginia DOT, Transportation and Mobility Planning
jeremy....@vdot.virginia.gov / 804-786-0998
-----Original Message-----
From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On
Behalf Of Albert-Jan Roskam
Sent: Tuesday, April 27, 2010 09:29 AM
To: R Mailing List
Subject: [R] sprintf() and return() oddity
Hi,
If I use sprintf and return inside a function, sprintf doesn't print anything
anymore. See the non-sense example below.
> x <- function() { a <- 888
+ sprintf("xxx %s", a) }
> x()
[1] "xxx 888"
> x <- function() { a <- 888
+ sprintf("xxx %s", a)
+ return(a) }
> x()
[1] 888
Is this a bug?
Cheers!!
Albert-Jan
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All right, but apart from the sanitation, the medicine, education, wine, public
order, irrigation, roads, a fresh water system, and public health, what have
the Romans ever done for us?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[[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.
