The “str_extract_all” Function in R

• Package: stringr

• Purpose: To extract all occurrences of a pattern in each element of a character vector.

• General Class: String Manipulation

• Required Argument(s):

• string: A character vector from which to extract patterns.

• pattern: The pattern to be extracted.

• Notable Optional Arguments:

• ...: Additional arguments influencing the extraction process, such as ignore_case to perform case-insensitive matching.

• Example:

• # Example usage
  library(stringr)
  
  sentence <- "The quick brown fox jumps over the lazy dog. The fox is a clever animal."
  
  # Extract all occurrences of "fox" in the sentence
  fox_extract_all <- str_extract_all(sentence, pattern = "fox")
  
  print(fox_extract_all)

• In this example, the str_extract_all function from the stringr package is used to extract all occurrences of the pattern “fox” in the character vector sentence. The result is a list where each element contains a character vector with the extracted patterns for the corresponding element in the original vector.