R help - Nov 2010 - '=' vs '<-'

Hi all,

can we use '=' instead of '<-' operator for assignment in R
programs?

regards,
KM

Yes, but <- is preferred. Note, there are also some differences. You can do
the following:
> a <- 10
> b = 10
> identical(a,b)
[1] TRUE

And you can also do
> myFun <- function(x, y = 100){
+ result <- x*y
+ result}
> myFun(x  = 20)
[1] 2000

But, you cannot use '<-' to define the arguments of a function
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at
r-project.org] On
> Behalf Of km
> Sent: Wednesday, November 03, 2010 2:05 PM
> To: r-help at r-project.org
> Subject: [R] '=' vs '<-'
> 
> Hi all,
> 
> can we use '=' instead of '<-' operator for assignment
in R programs?
> 
> regards,
> KM
> 
> ______________________________________________
> R-help at 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.

On Wed, Nov 3, 2010 at 6:04 PM, km <srikrishnamohan at gmail.com>
wrote:
> Hi all,
>
> can we use '=' instead of '<-' operator for assignment
in R programs?
 Yes, mostly, you can also use 'help' to ask such questions:

 > help("=")

    The operators ?<-? and ?=? assign into the environment in which
     they are evaluated.  The operator ?<-? can be used anywhere,
     whereas the operator ?=? is only allowed at the top level (e.g.,
     in the complete expression typed at the command prompt) or as one
     of the subexpressions in a braced list of expressions.

and so on...

@all:  Does it seem reasonable to add a discussion of '=' vs.
'<-' to
the FAQ?  It seems a regular question and something of a "hot" topic
to debate.

@KM  Here are links I've accumulated to prior discussions on this
topic.  I am pretty certain they are all unique.


http://blog.revolutionanalytics.com/2008/12/use-equals-or-arrow-for-assignment.html

http://www.mail-archive.com/r-help at r-project.org/msg69310.html

http://www.mail-archive.com/r-help at r-project.org/msg99789.html

http://www.mail-archive.com/r-help at r-project.org/msg104102.html

http://www.mail-archive.com/r-help at r-project.org/msg16881.html

https://stat.ethz.ch/pipermail/r-sig-teaching/2010q4/000312.html

http://r.789695.n4.nabble.com/advice-opinion-on-vs-in-teaching-R-td1014502.html#a1014502


On Wed, Nov 3, 2010 at 11:04 AM, km <srikrishnamohan at gmail.com>
wrote:
> Hi all,
>
> can we use '=' instead of '<-' operator for assignment
in R programs?
>
> regards,
> KM
>
> ______________________________________________
> R-help at 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.


-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/