Count number of dots in character string with str_count?

Question

I am trying to count the number of dots in a character string.

I have tried to use str_count but it gives me the number of letters of the string instead.

ex_str <- "This.is.a.string" 
str_count(ex_str, '.')
nchar(ex_str)

Answer 1

. is a special regex symbol, so you need to escape it:

str_count(ex_str, '\\.')
# [1] 3

Using just base R you could do:

nchar(gsub("[^.]", "", ex_str))

Using stringi:

stri_count_fixed(ex_str, '.')