str_detect() returns a logical vector with TRUE for each element of
string that matches pattern and FALSE otherwise. It's equivalent to
grepl(pattern, string).
str_detect(string, pattern, negate = FALSE)Input vector. Either a character vector, or something coercible to one.
Pattern to look for.
The default interpretation is a regular expression, as described in
vignette("regular-expressions"). Use regex() for finer control of the
matching behaviour.
Match a fixed string (i.e. by comparing only bytes), using
fixed(). This is fast, but approximate. Generally,
for matching human text, you'll want coll() which
respects character matching rules for the specified locale.
Match character, word, line and sentence boundaries with
boundary(). An empty pattern, "", is equivalent to
boundary("character").
If TRUE, inverts the resulting boolean vector.
A logical vector the same length as string/pattern.
stringi::stri_detect() which this function wraps,
str_subset() for a convenient wrapper around
x[str_detect(x, pattern)]
fruit <- c("apple", "banana", "pear", "pineapple")
str_detect(fruit, "a")
#> [1] TRUE TRUE TRUE TRUE
str_detect(fruit, "^a")
#> [1] TRUE FALSE FALSE FALSE
str_detect(fruit, "a$")
#> [1] FALSE TRUE FALSE FALSE
str_detect(fruit, "b")
#> [1] FALSE TRUE FALSE FALSE
str_detect(fruit, "[aeiou]")
#> [1] TRUE TRUE TRUE TRUE
# Also vectorised over pattern
str_detect("aecfg", letters)
#> [1] TRUE FALSE TRUE FALSE TRUE TRUE TRUE FALSE FALSE FALSE FALSE FALSE
#> [13] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
#> [25] FALSE FALSE
# Returns TRUE if the pattern do NOT match
str_detect(fruit, "^p", negate = TRUE)
#> [1] TRUE TRUE FALSE FALSE