Scope

Scope

Variables created inside a function are local to that function's execution and disappear once it returns, without affecting variables of the same name outside. R uses lexical scoping, meaning a function can read variables from its enclosing environment, but assignments inside the function create new local variables by default rather than modifying the outer one. The <<- operator can explicitly modify a variable in an enclosing scope, though it's used sparingly.

Warning: Assigning to a variable inside a function with <- creates a new local variable -- it does not modify a same-named variable outside the function.

Example: Scope

x <- "global value"

show_scope <- function() {
  x <- "local value"
  cat("Inside function:", x, "\n")
}

show_scope()
cat("Outside function:", x, "\n")