Revision a7a4cbc3dc2cc4ef571589a67ab11ef5688a1ac0 authored by Gregory Warnes on 12 October 2012, 00:00:00 UTC, committed by Gabor Csardi on 12 October 2012, 00:00:00 UTC
1 parent 694c281
startsWith.Rd
\name{startsWith}
\alias{startsWith}
\title{
Determine if a character string "starts with" with the specified characters.
}
\description{
Determine if a character string "starts with" with the specified characters.
}
\usage{
startsWith(str, pattern, trim=FALSE, ignore.case=FALSE)
}
\arguments{
\item{str}{character vector to test}
\item{pattern}{characters to check for}
\item{trim}{Logical flag indicating whether leading whitespace should
be removed from \code{str} before testing for a match.}
\item{ignore.case}{Logical flag indicating whether case should be
ignored when testing for a match.}
}
\details{
This function returns TRUE for each element of the vector \code{str}
where \code{pattern} occurs at the beginning of the string. If
\code{trim} is TRUE, leading whitespace is removed from the elements
of \code{str} before the test is performed. If \code{ignore.case} is
TRUE, character case is ignored.
}
\value{
Boolean vector of the same length as \code{str}.
}
\author{
Gregory R. Warnes \email{greg@warnes.net}
}
\seealso{
\code{\link[base]{substr}}, \code{\link{trim}}
}
\examples{
## simplest example:
startsWith( 'Testing', 'Test')
## vector examples
s <- c('Testing', ' Testing', 'testing', 'Texting')
names(s) <- s
startsWith(s, 'Test') # ' Testing', 'testing', and 'Texting' do not match
startsWith(s, 'Test', trim=TRUE) # Now ' Testing' matches
startsWith(s, 'Test', ignore.case=TRUE) # Now 'testing' matches
}
\keyword{character}
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