CODE EXAMPLE FOR R

regex in R

x <- "1888 is the longest year in Roman numerals: MDCCCLXXXVIII"
str_extract(x, "CC?")
#> [1] "CC"
str_extract(x, "CC+")
#> [1] "CCC"
str_extract(x, 'C[LX]+')
#> [1] "CLXXX"