count the number of occurrences of “(” in a string

Question

I am trying to get the number of open brackets in a character string in R. I am using the str_count function from the stringr package

Answer 1

If you want to do it in base R you can split into a vector of individual characters and count the "(" directly (without representing it as a regular expression):

> s<- "(hi),(bye),(hi)"
> chars <- unlist(strsplit(s,""))
> length(chars[chars == "("])
[1] 3