summarize_many_vars

library(tidyverse)

mtcars %>% 
  select(starts_with("c")) %>% 
  summarise_all(mean)

mega_lm <- function(var) {
  fmla <- as.formula(paste("mpg ~", var))
  lm(fmla, data = mtcars) %>% 
    tidy()
}

# purrr
map_dfr(c("hp", "cyl"), mega_lm, .id = "model")