R help - Mar 2014 - Issue with special assignment operator

Hi

Please explain why the function 'foo()' is not printing x as 8 in the
following code :
> foo <- function(){
+ x <- 10
+ if(x){
+ x <<- 8
+ }
+ print(x)
+ }
> foo()
[1] 10
> x
[1] 8
>
-- 
*AROONALOK PYNE*

BE Graduate
Department Of Computer Science And Engineering
Jadavpur University, Kolkata-32
India

Because x refers to the local version, not the global one.

In case you have not read this before, using <<- is a really really bad
idea. Your code will become confusing and likely be wrong if you ignore this
warning. Return a value from the function and save it in the calling environment
when you call the function.
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On March 16, 2014 9:06:13 PM PDT, AROONALOK PYNE <aroonalok.pyne at
gmail.com> wrote:
>Hi
>
>Please explain why the function 'foo()' is not printing x as 8 in
the
>following code :
>
>> foo <- function(){
>+ x <- 10
>+ if(x){
>+ x <<- 8
>+ }
>+ print(x)
>+ }
>> foo()
>[1] 10
>> x
>[1] 8
>>