Change value of variable with dplyr?

Question

I regularly need to change the values of a variable based on the values on a different variable, like this: mtcars$mpg[mtcars$cyl == 4] <- NAI tried doing this with `dplyr` but failed miserably: mtcars %>% mutate(mpg = mpg == NA[cyl == 4]) %>% as.data.frame()How could I do this with `dplyr`?

Answer 1

mtcars <- mtcars %>%

mutate(mpg = ifelse(cyl == 4, NA, mpg))