select columns based on multiple strings with dplyr contains()

Question

I want to select multiple columns based on their names with a regex expression. I am trying to do it with the piping syntax of the dplyr package. I che

Answer 1

You can use matches

 mtcars %>%
        select(matches('m|ar')) %>%
        head(2)
 #              mpg am gear carb
 #Mazda RX4      21  1    4    4
 #Mazda RX4 Wag  21  1    4    4

According to the ?select documentation

‘matches(x, ignore.case = TRUE)’: selects all variables whose name matches the regular expression ‘x’

Though contains work with a single string

mtcars %>% 
       select(contains('m'))