The “str_extract” Function in R

• Package: stringr

• Purpose: To extract the first occurrence 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 the first occurrence of "fox" in the sentence
  fox_extract <- str_extract(sentence, pattern = "fox")
  
  print(fox_extract)

• In this example, the str_extract function from the stringr package is used to extract the first occurrence of the pattern “fox” in the character vector sentence. The result is a character vector containing the extracted patterns.