[R] How to make the assignment in a for-loop not affect variables outside the loop?

[Uwe Ligges]

Either use local as in:

n=10

local(for(i in 1:n){
      n=3
      print(n)
})

print(n)


or write a function that is evaluated in its own environment:

n=10

MyLoopFoo <- function(){
     for(i in 1:n){
         n <- 3
         print(n)
     }
}

MyLoopFoo()

print(n)




Uwe Ligges


Peng Yu wrote:
> I know that R is a dynamic programming language. But I'm wondering if
> there is a way to make the assignment in a for-loop not affect
> variables outside the loop.
> 
>> n=10
>> for(i in 1:n){
> +     n=3
> +     print(n)
> + }
> [1] 3
> [1] 3
> [1] 3
> [1] 3
> [1] 3
> [1] 3
> [1] 3
> [1] 3
> [1] 3
> [1] 3
>> print(n)
> [1] 3
> 
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