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\name{str_extract}
\alias{str_extract}
\title{Extract first piece of a string that matches a pattern.}
\usage{
str_extract(string, pattern)
}
\arguments{
\item{string}{input vector. This must be an atomic
vector, and will be coerced to a character vector}
\item{pattern}{pattern to look for, as defined by a POSIX
regular expression. See the ``Extended Regular
Expressions'' section of \code{\link{regex}} for details.
See \code{\link{fixed}}, \code{\link{ignore.case}} and
\code{\link{perl}} for how to use other types of
matching: fixed, case insensitive and perl-compatible.}
}
\value{
character vector.
}
\description{
Vectorised over \code{string}. \code{pattern} should be
a single pattern, i.e. a character vector of length one.
}
\examples{
shopping_list <- c("apples x4", "flour", "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")
}
\seealso{
\code{\link{str_extract_all}} to extract all matches
}
\keyword{character}
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