Idk why, but looking at the traditional base-R functions really hurt my eyes. The inconsistent api (like in gsub, where the string comes last) together with the unclear naming (very Unixy when you think about it) made it very hard for me when getting starting with R.

Now days I would do the same with the tidyverse equivalents:

    my_column %>% 
      stringr::str_replace_all(" ","") %>% 
      stringr::str_replace_all("[a-zA-Z]+","") %>% 
      stringr::str_split("-") %>% 
      purrr::map(is.numeric) %>% 
      purrr::map(mean)