Detect matches in strings

Detect matching pattern in character vector.

chr_detect(x, pat, ignore.case = FALSE, ...)

Arguments

x	Character vector
pat	Pattern (regex) to detect from text.
ignore.case	Logical indicating whether to ignore capitalization. Defaults to false.
...	Other named arguments passed to grepl or grep See details for more information.

Value

Logical vector indicating whether each element matched the supplied pattern.

Details

This is a wrapper around the base R functions grepl and grep. By default, logical values are returned (a la grepl). To return values, include value = TRUE. To return positions, include which = TRUE, pos = TRUE, or position = TRUE.

Examples

## return logical vector
chr_detect(letters, "a|b|c|x|y|z")
#>  [1]  TRUE  TRUE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
#> [13] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE
#> [25]  TRUE  TRUE

## return inverted logical values
chr_detect(letters, "a|b|c|x|y|z", invert = TRUE)
#>  [1] FALSE FALSE FALSE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE
#> [13]  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE FALSE
#> [25] FALSE FALSE

## return matching positions
chr_detect(letters, "a|b|c|x|y|z", which = TRUE)
#> [1]  1  2  3 24 25 26

## return inverted matching positions
chr_detect(letters, "a|b|c|x|y|z", which = TRUE, invert = TRUE)
#>  [1]  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

## return matching values
chr_detect(letters, "a|b|c|x|y|z", value = TRUE)
#> [1] "a" "b" "c" "x" "y" "z"

## return inverted matching values
chr_detect(letters, "a|b|c|x|y|z", value = TRUE, invert = TRUE)
#>  [1] "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v"
#> [20] "w"