There are three methods you can use to count the number of words in a string in R:

Method 1: Use Base R

lengths(strsplit(my_string, ' '))

Method 2: Use stringi Package

library(stringi)

stri_count_words(my_string)

Method 3: Use stringr Package

library(stringr)

str_count(my_string, 'w+')

Each of these methods will return a numerical value that represents the number of words in the string called my_string.

The following examples show how to use each of these methods in practice.

Example 1: Count Words Using Base R

The following code shows how to count the number of words in a string using the lengths and strsplit functions from base R:

#create string
my_string <- 'this is a string with seven words'

#count number of words in string
lengths(strsplit(my_string, ' '))

[1] 7

From the output we can see that there are seven words in the string.

Example 2: Count Words Using stringi Package

The following code shows how to count the number of words in a string using the stri_count_words function from the stringi package in R:

library(stringi) 

#create string
my_string <- 'this is a string with seven words'

#count number of words in string
stri_count_words(my_string)

[1] 7

Example 3: Count Words Using stringr Package

The following code shows how to count the number of words in a string using the str_count function from the stringr package in R:

library(stringr) 

#create string
my_string <- 'this is a string with seven words'

#count number of words in string
str_count(my_string, 'w+')

[1] 7

From the output we can see that there are seven words in the string.

Note that we used the regular expression w+ to match non-word characters with the + sign to indicate one or more in a row.

Note: In each of these examples we counted the number of words in a single string, but each method will also work with a vector of strings.