Adding column if it does not exist

Question

I have a bunch of data frames with different variables. I want to read them into R and add columns to those that are short of a few variables so that they all have a common

Answer 1

Another option that does not require creating a helper function (or an already complete data.frame) using tibble's add_column:

library(tibble)

cols <- c(top_speed = NA_real_, nhj = NA_real_, mpg = NA_real_)

add_column(mtcars, !!!cols[setdiff(names(cols), names(mtcars))])