Example 1: Counting characters with base R

Base R provides a simple way to count the number of times a character occurs using the gregexpr() function. This function returns the positions of the pattern in the string, which we can then count.

Example:

# Define the string
text  0)
count

Explanation:

• gregexpr() looks for a pattern (in this case the sign "o") within a string and returns the positions of all matches.
• unlist() is used to convert the list of positions into a vector.
• sum(unlist(matches) > 0) counts the number of positions where a match was found.

This method is direct and effective, especially if you want to preserve the basic functionality of R.

Example 2: Counting characters with stringr

The stringr package, part of the tidyverse, provides a more user-friendly syntax for string manipulation. The str_count() function is perfect for counting characters.

Example:

# Load the stringr package
library(stringr)

# Define the string
text 

Explanation:

• str_count() counts the number of times a pattern occurs in a string.
• The first argument is the string to search for, and the second is the pattern to count.

This method is concise and integrates well with other tidyverse functions.

Example 3: Counting characters with stringi

The stringi package offers extensive and powerful string manipulation tools and is known for its efficiency. stri_count_fixed() This function allows you to count fixed patterns.

Example:

# Load the stringi package
library(stringi)

# Define the string
text 

Explanation:

• stri_count_fixed() counts the exact number of times a fixed pattern occurs in the string.
• The feature is optimized for performance, making it suitable for large-scale word processing tasks.