Scope in R

I could never figure out how scoping works in R, so I pasted it here. Bottom line: things like if blocks do not have their own scope.

> x <- 1
> y <- 2
> z <- 3
>
> my.func <- function() {
+   print(sprintf("%d %d %d %d", x, y, z, w))
+   y <- 102
+   if (TRUE) {
+     z <- 103
+     w <- 104
+     print(sprintf("%d %d %d %d", x, y, z, w))
+   }
+   print(sprintf("%d %d %d %d", x, y, z, w))
+ }
>
>
> if (TRUE) {
+   w <- 4
+ }
> print(sprintf("%d %d %d %d", x, y, z, w))
[1] "1 2 3 4"
>
> print("Calling my.func")
[1] "Calling my.func"
> my.func()
[1] "1 2 3 4"
[1] "1 102 103 104"
[1] "1 102 103 104"
> print("Done with my.func")
[1] "Done with my.func"
>
> print(sprintf("%d %d %d %d", x, y, z, w))
[1] "1 2 3 4"