在 R 中查找多个字符串内匹配项

Question

As the title says, I am looking to locate and count multiple matches of a target string within a larger string. For example:

# looking for 
target <- "zoo"
# in this
word <- "zoozoo"

I have tried a few different things such as:

regexpr(target, word)

and

regmatches(word, regexpr(target, word))

But neither of these finds both of the substrings ie "zoo" and "zoo" . I am trying to write something that will find and count all of the matches, there will be multiple in what I am trying to do.

Your help is much appreciated.

Answer 1

You may use str_count to count all the matched occurrences.

library(stringr)
str_count(word, target)

Answer 2

If you need both the positions of the substrings and the count, you might try

positions <- unlist(gregexpr(target, word))
count <- length(positions)