# No out parameters: the function gets a name
# and writes it into the caller's frame.
# Rare in R: usually the value is returned
get_sum <- function(out_name, n1, n2) {
assign(out_name, n1 + n2,
envir = parent.frame())
}
get_sum("ar_sum", 5, 3)
# ar_sum = 8
cat("ar_sum =", ar_sum, "\n")