R help - Feb 2010 - Is there a way to make blocks of code independent from each other?

I'm wondering if there is a way to make blocks of code independent
from each other. Please see the following example for what I mean.

x=1

## is there a way to make the following assignment not affect the above x?
## in C++, I can use {} to make the effect local. Is there an
equivalent construct in R?
x=3
<do something with the new value of x>
###

print(x) # I don't want the value of x change to 3.

Put in a function what you would have put in the {} and execute the function

x=1
myf=function()
{
   x=3
   do something with new value of x
   ...
}
myf()

print(x)  # it will be 1

On 1/31/2010 5:56 PM, Peng Yu wrote:
> I'm wondering if there is a way to make blocks of code independent
> from each other. Please see the following example for what I mean.
>
> x=1
>
> ## is there a way to make the following assignment not affect the above x?
> ## in C++, I can use {} to make the effect local. Is there an
> equivalent construct in R?
> x=3
> <do something with the new value of x>
> ###
>
> print(x) # I don't want the value of x change to 3.
>
> ______________________________________________
> 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.
>

Use 'local'
> x <- 1
> local({
+     x <- 3
+     print(x)
+ })
[1] 3
> print(x)
[1] 1
>
>

On Sun, Jan 31, 2010 at 8:56 PM, Peng Yu <pengyu.ut at gmail.com>
wrote:
> I'm wondering if there is a way to make blocks of code independent
> from each other. Please see the following example for what I mean.
>
> x=1
>
> ## is there a way to make the following assignment not affect the above x?
> ## in C++, I can use {} to make the effect local. Is there an
> equivalent construct in R?
> x=3
> <do something with the new value of x>
> ###
>
> print(x) # I don't want the value of x change to 3.
>
> ______________________________________________
> 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.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?