vector_to_code <- function(vec, vec_name) {
  if (is.character(vec)) {
    paste0(vec_name, " <- c('", paste0(vec, collapse = "', '"), "')")
  } else {
    paste0(vec_name, " <- c(", paste0(vec, collapse = ", "), ")")
  }
}

# example
a <- c(1, 2, 3)
vector_to_code(a, "a_new")
b <- c("a", "b", "c")
vector_to_code(b, "b_new")