The R Project SVN R

\name{function}
\title{Function Definition}
\usage{
function( arglist ) expr
return(value)
}
\alias{function}
\alias{return}
\description{
These functions provide the base mechanisms for defining
new functions in the \R language.
}
\arguments{
    \item{arglist}{Empty or one or more name or name=expression terms.}
    \item{value}{An expression, or a series of non-empty expressions separated
        by commas.}
}
\details{
    In \R (unlike S) the names in an argument list cannot be quoted
    non-standard names.

    If \code{value} is missing, \code{NULL} is returned.  If it is a
    single expression, the value of the evaluated expression is returned.

    If \code{value} is a series of non-empty expressions, the value
    returned is a list of the evaluated expressions, with names set to
    the expressions where these are the names of \R objects. That is,
    \code{a=foo()} names the list component \code{a} and gives it value
    the result of evaluating \code{foo()}.

}
\seealso{
  \code{\link{args}} and \code{\link{body}} for accessing the arguments
  and body of a function.

  \code{\link{debug}} for debugging; \code{\link{invisible}} for
  \code{return(.)}ing \emph{invisibly}.
}
\examples{
norm <- function(x) sqrt(x\%*\%x)
norm(1:4)

## An anonymous function:
(function(x,y){ z <- x^2 + y^2; x+y+z })(0:7, 1)
}
\keyword{programming}