Extract matching patterns from a string.
Vectorised over string and pattern.
str_extract(string, pattern) str_extract_all(string, pattern, simplify = FALSE)
string |
Input vector. Either a character vector, or something coercible to one. |
pattern |
Pattern to look for. The default interpretation is a regular expression, as described
in stringi::stringi-search-regex. Control options with
Match a fixed string (i.e. by comparing only bytes), using
Match character, word, line and sentence boundaries with
|
simplify |
If |
A character vector.
str_match() to extract matched groups;
stringi::stri_extract() for the underlying implementation.
shopping_list <- c("apples x4", "bag of flour", "bag of sugar", "milk x2")
str_extract(shopping_list, "\\d")
str_extract(shopping_list, "[a-z]+")
str_extract(shopping_list, "[a-z]{1,4}")
str_extract(shopping_list, "\\b[a-z]{1,4}\\b")
# Extract all matches
str_extract_all(shopping_list, "[a-z]+")
str_extract_all(shopping_list, "\\b[a-z]+\\b")
str_extract_all(shopping_list, "\\d")
# Simplify results into character matrix
str_extract_all(shopping_list, "\\b[a-z]+\\b", simplify = TRUE)
str_extract_all(shopping_list, "\\d", simplify = TRUE)
# Extract all words
str_extract_all("This is, suprisingly, a sentence.", boundary("word"))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.